X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fcmm%2FCmmCPS.hs;h=acdd2a6bc4f2687d4bde54b717a5d3e26c6fc2d6;hp=4394fb595e8e8f8faed34c99e7dec3eba1e88170;hb=e6243a818496aad82b6f47511d3bd9bc800f747d;hpb=af452780391355f7008fe97e556ced25a3dd2d21 diff --git a/compiler/cmm/CmmCPS.hs b/compiler/cmm/CmmCPS.hs index 4394fb5..acdd2a6 100644 --- a/compiler/cmm/CmmCPS.hs +++ b/compiler/cmm/CmmCPS.hs @@ -1,3 +1,10 @@ +{-# OPTIONS -w #-} +-- The above warning supression flag is a temporary kludge. +-- While working on this module you are encouraged to remove it and fix +-- any warnings in the module. See +-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings +-- for details + module CmmCPS ( -- | Converts C-- with full proceedures and parameters -- to a CPS transformed C-- with the stack made manifest. @@ -6,6 +13,7 @@ module CmmCPS ( #include "HsVersions.h" +import BlockId import Cmm import CmmLint import PprCmm @@ -14,20 +22,14 @@ import CmmLive import CmmBrokenBlock import CmmProcPoint import CmmCallConv -import CmmInfo +import CmmCPSGen 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 @@ -41,122 +43,97 @@ 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" + -> [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 doCpsProc s (Cmm c) = - Cmm $ concat $ zipWith cpsProc (listSplitUniqSupply s) c - let continuationC = zipWith doCpsProc supplies abstractC + ; 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 continuationC) + ; dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "CPS Cmm" (pprCmms cpsd_cmm) -- TODO: add option to dump Cmm to file - return continuationC + ; return cpsd_cmm } -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. ----------------------------------------------------------------------------- +doCpsProc :: UniqSupply -> Cmm -> Cmm +doCpsProc s (Cmm c) + = Cmm $ concat $ zipWith cpsProc (listSplitUniqSupply s) c + 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 + -> 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 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 _ _ _ (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 - (gc_unique:stack_use_unique:info_uniques):adaptor_uniques:block_uniques = uniques - proc_uniques = map (map uniqsFromSupply . listSplitUniqSupply) $ listSplitUniqSupply uniqSupply2 + (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 (cmmRegRep spReg) KindPtr) + 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) - -- 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) @@ -184,10 +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 @@ -202,69 +177,35 @@ 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 - +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 + 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 :: @@ -278,7 +219,7 @@ collectNonProcPointTargets proc_points blocks current_targets new_blocks = new_targets (map (:[]) targets) where - blocks' = map (lookupWithDefaultUFM blocks (panic "TODO")) new_blocks + 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, @@ -295,19 +236,15 @@ 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 = lookupWithDefaultBEnv blocks unknown_block start + children_blocks = map (lookupWithDefaultBEnv 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 @@ -315,7 +252,7 @@ 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 @@ -331,7 +268,7 @@ gatherBlocksIntoContinuation live proc_points blocks start gc = ContinuationEntry args _ _ -> args ControlEntry -> uniqSetToList $ - lookupWithDefaultUFM live unknown_block start + lookupWithDefaultBEnv live unknown_block start -- it's a proc-point, pass lives in parameter registers -------------------------------------------------------------------------------- @@ -345,7 +282,7 @@ selectContinuationFormat live 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 @@ -359,14 +296,16 @@ selectContinuationFormat live continuations = in (formals, Just label, map Just $ uniqSetToList $ - lookupWithDefaultUFM live unknown_block ident) + 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, [(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 @@ -382,6 +321,17 @@ 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 = (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 @@ -389,7 +339,7 @@ processFormats formats continuations = (max_size, formats') 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 + width = (widthInBytes $ typeWidth $ localRegType reg) `quot` wORD_SIZE -- TODO: it would be better if we had a machRepWordWidth continuationMaxStack :: [(CLabel, ContinuationFormat)] @@ -409,14 +359,14 @@ continuationMaxStack formats (Continuation _ label _ False blocks) = map stmt_arg_size (brokenBlockStmts block)) final_arg_size (FinalReturn args) = - argumentsSize (cmmExprRep . fst) args + argumentsSize (cmmExprType . hintlessCmm) 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) = + argumentsSize (cmmExprType . hintlessCmm) 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 + + argumentsSize (cmmExprType . hintlessCmm) args + continuation_frame_size next_format where next_format = maybe unknown_format id $ lookup next' formats @@ -425,8 +375,8 @@ continuationMaxStack formats (Continuation _ label _ False blocks) = final_arg_size _ = 0 stmt_arg_size (CmmJump _ args) = - argumentsSize (cmmExprRep . fst) args - stmt_arg_size (CmmCall _ _ _ (CmmSafe _)) = + argumentsSize (cmmExprType . hintlessCmm) args + stmt_arg_size (CmmCall _ _ _ (CmmSafe _) _) = panic "Safe call in processFormats" stmt_arg_size (CmmReturn _) = panic "CmmReturn in processFormats" @@ -438,10 +388,11 @@ applyContinuationFormat :: [(CLabel, ContinuationFormat)] -> 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)) +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 @@ -455,7 +406,7 @@ 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 undefined prof tag (ContInfo (continuation_stack $ format) srt))) label formals is_gc blocks where gc = Nothing -- Generated continuations never need a stack check @@ -466,400 +417,3 @@ 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" - --- 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 - 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 - (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 - -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 -- ^ 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 - -- (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)) -