X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fcmm%2FCmmCPS.hs;h=53f54bf5a6efdcc43dfde1d9914669d0eac442a2;hb=8a2809c29de9f23eba7ca682b48390033a9d40f6;hp=e6d70d4b3d145b0c300a25a93bdbccc54eeda4e6;hpb=a2d5d3c9677a740ace920a976d03dfbd82f7697b;p=ghc-hetmet.git diff --git a/compiler/cmm/CmmCPS.hs b/compiler/cmm/CmmCPS.hs index e6d70d4..53f54bf 100644 --- a/compiler/cmm/CmmCPS.hs +++ b/compiler/cmm/CmmCPS.hs @@ -14,10 +14,9 @@ import CmmLive import CmmBrokenBlock import CmmProcPoint import CmmCallConv -import CmmInfo +import CmmCPSGen import CmmUtils -import Bitmap import ClosureInfo import MachOp import ForeignCall @@ -43,7 +42,7 @@ import Data.List ----------------------------------------------------------------------------- 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-- + -> IO [GenCmm CmmStatic CmmInfo CmmStmt] -- ^ Output CPS transformed C-- cmmCPS dflags abstractC = do when (dopt Opt_DoCmmLinting dflags) $ do showPass dflags "CmmLint" @@ -69,41 +68,23 @@ cmmCPS dflags abstractC = do 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 +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 - 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' + 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 $ cmmRegRep 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 _ _ + -> [] ----------------------------------------------------------------------------- -- |CPS a single CmmTop (proceedure) @@ -112,42 +93,47 @@ force_gc_block old_info stack_use block_id fun_label formals = 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 + -> [GenCmmTop CmmStatic CmmInfo CmmStmt] -- ^Output proceedure and continuations + +-- Data blocks don't need to be CPS transformed +cpsProc uniqSupply 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 uniqSupply proc@(CmmProc _ _ _ []) = [proc] + +-- CPS transform for those procs that actually need it +cpsProc uniqSupply (CmmProc info ident params 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 - (gc_unique:stack_use_unique:info_uniques):adaptor_uniques:block_uniques = uniques - proc_uniques = map uniqsFromSupply $ listSplitUniqSupply uniqSupply2 + (stack_check_block_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) + 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) - -- 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 = stack_check_block : blocks - 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 + 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 [forced_gc_id]) + zipWith3 (breakBlock (maybeToList maybe_gc_block_id)) block_uniques forced_blocks - (FunctionEntry forced_info ident params : + (FunctionEntry info ident params : repeat ControlEntry) f' = selectContinuations (fst broken_blocks) @@ -175,10 +161,8 @@ cpsProc uniqSupply (CmmProc info ident params blocks) = info_procs -- 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-} + 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 @@ -193,69 +177,18 @@ cpsProc uniqSupply (CmmProc info ident params blocks) = info_procs -- 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 + 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 (snd formats')) continuations + continuations' = map (applyContinuationFormat format_list) 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 --- 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). - -continuationLabel (Continuation _ l _ _ _) = l -data Continuation info = - Continuation - 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) - 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. - - -- the BlockId of the first block does not give rise - -- to a label. To jump to the first block in a Proc, - -- use the appropriate CLabel. - -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 - ----------------------------------------------------------------------------- collectNonProcPointTargets :: @@ -286,19 +219,15 @@ collectNonProcPointTargets proc_points blocks current_targets new_blocks = gatherBlocksIntoContinuation :: BlockEntryLiveness -> UniqSet BlockId -> BlockEnv BrokenBlock - -> BlockId -> Maybe BlockId -> Continuation (Either C_SRT CmmInfo) -gatherBlocksIntoContinuation live proc_points blocks start gc = + -> BlockId -> Continuation (Either C_SRT CmmInfo) +gatherBlocksIntoContinuation live proc_points blocks start = Continuation info_table clabel params is_gc_cont body where - --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 + start_block = lookupWithDefaultUFM blocks unknown_block start + children_blocks = map (lookupWithDefaultUFM blocks unknown_block) (uniqSetToList children) 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 : {-gc_block ++ -} children_blocks + body = start_block : children_blocks -- We can't properly annotate the continuation's stack parameters -- at this point because this is before stack selection @@ -306,7 +235,7 @@ gatherBlocksIntoContinuation live proc_points blocks start gc = info_table = case start_block_entry of FunctionEntry info _ _ -> Right info ContinuationEntry _ srt _ -> Left srt - ControlEntry -> Right (CmmNonInfo Nothing) + ControlEntry -> Right (CmmInfo Nothing Nothing CmmNonInfoTable) is_gc_cont = case start_block_entry of FunctionEntry _ _ _ -> False @@ -334,10 +263,13 @@ selectContinuationFormat :: BlockEnv CmmLive selectContinuationFormat live continuations = map (\c -> (continuationLabel c, selectContinuationFormat' c)) continuations where + -- User written continuations selectContinuationFormat' (Continuation - (Right (CmmInfo _ _ _ (ContInfo format srt))) + (Right (CmmInfo _ _ (CmmInfoTable _ _ (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 @@ -352,9 +284,11 @@ selectContinuationFormat live continuations = unknown_block = panic "unknown BlockId in selectContinuationFormat" processFormats :: [(CLabel, (CmmFormals, Maybe CLabel, [Maybe LocalReg]))] + -> Maybe UpdateFrame -> [Continuation (Either C_SRT CmmInfo)] - -> (WordOff, [(CLabel, ContinuationFormat)]) -processFormats formats continuations = (max_size, formats') + -> (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 @@ -370,6 +304,17 @@ processFormats formats continuations = (max_size, formats') 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 = machRepByteWidth (cmmExprRep expr) `quot` wORD_SIZE + -- TODO: it would be better if we had a machRepWordWidth + -- TODO: get rid of "+ 1" etc. label_size = 1 :: WordOff @@ -427,15 +372,15 @@ applyContinuationFormat :: [(CLabel, ContinuationFormat)] -- User written continuations applyContinuationFormat formats (Continuation - (Right (CmmInfo prof gc tag (ContInfo _ srt))) + (Right (CmmInfo gc update_frame (CmmInfoTable prof tag (ContInfo _ srt)))) label formals is_gc blocks) = - Continuation (CmmInfo prof gc tag (ContInfo format srt)) + Continuation (CmmInfo gc update_frame (CmmInfoTable 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" --- User written non-continuation code +-- 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 @@ -443,7 +388,7 @@ applyContinuationFormat formats (Continuation -- CPS generated continuations applyContinuationFormat formats (Continuation (Left srt) label formals is_gc blocks) = - Continuation (CmmInfo prof gc tag (ContInfo (continuation_stack $ format) srt)) + Continuation (CmmInfo gc Nothing (CmmInfoTable prof tag (ContInfo (continuation_stack $ format) srt))) label formals is_gc blocks where gc = Nothing -- Generated continuations never need a stack check @@ -454,218 +399,3 @@ applyContinuationFormat formats (Continuation 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" - - continuationToProc' :: Unique -> BrokenBlock -> Bool -> [CmmBasicBlock] - continuationToProc' unique (BrokenBlock ident entry stmts _ exit) is_entry = - case gc_prefix ++ param_prefix of - [] -> [main_block] - stmts -> [BasicBlock prefix_id (gc_prefix ++ param_prefix ++ [CmmBranch ident]), - main_block] - where - main_block = BasicBlock ident (stmts ++ postfix) - prefix_id = BlockId unique - gc_prefix = case entry of - FunctionEntry _ _ _ -> gc_stmts - ControlEntry -> [] - ContinuationEntry _ _ _ -> [] - param_prefix = if is_entry - then param_stmts - else [] - postfix = 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) - formal_to_actual reg = (CmmReg (CmmLocal reg), NoHint) - 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 - 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 - cont_stack = continuation_frame_size cont_format - FinalCall next _ results arguments _ _ -> panic "unimplemented CmmCall" - ------------------------------------------------------------------------------ --- Functions that generate CmmStmt sequences --- for packing/unpacking continuations --- and entering/exiting functions - -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] - - 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*wORD_SIZE), - CmmReg spLimReg]) - gc_block] - - --- TODO: fix branches to proc point --- (we have to insert a new block to marshel the continuation) -pack_continuation :: Bool -> ContinuationFormat -> ContinuationFormat -> [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 - -- (may be handled by latter pass) - store_live_values = - [stack_put spRel (CmmReg (CmmLocal reg)) offset - | (reg, offset) <- cont_offsets] - 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). -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 = - [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] - - argument_formats = assignArguments (localRegRep) formals - - -- TODO: eliminate copy/paste with pack_continuation - curr_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 - ------------------------------------------------------------------------------ --- 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 - --------------------------------- --- |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)) -