X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fcmm%2FCmmCPS.hs;h=35eabb331704e26e3a83cb8468b661105e3eeb36;hp=e4a17a9795cdcdf78b830b192c7523a9fb696651;hb=643397208b83f1654bceeef40c793f11592ef816;hpb=d1ccf953188743a03966b7275f037637ef82a942 diff --git a/compiler/cmm/CmmCPS.hs b/compiler/cmm/CmmCPS.hs index e4a17a9..35eabb3 100644 --- a/compiler/cmm/CmmCPS.hs +++ b/compiler/cmm/CmmCPS.hs @@ -1,581 +1,171 @@ +{-# OPTIONS_GHC -XNoMonoLocalBinds #-} +-- Norman likes local bindings +-- If this module lives on I'd like to get rid of this flag in due course + module CmmCPS ( -- | Converts C-- with full proceedures and parameters -- to a CPS transformed C-- with the stack made manifest. - cmmCPS + -- Well, sort of. + protoCmmCPS ) where -#include "HsVersions.h" - +import CLabel import Cmm -import CmmLint -import PprCmm - -import CmmLive -import CmmBrokenBlock +import CmmDecl +import CmmBuildInfoTables +import CmmCommonBlockElim import CmmProcPoint -import CmmCallConv -import CmmInfo -import CmmUtils - -import Bitmap -import ClosureInfo -import MachOp -import ForeignCall -import CLabel -import SMRep -import Constants +import CmmSpillReload +import CmmStackLayout +import OptimizationFuel import DynFlags import ErrUtils -import Maybes +import HscTypes +import Data.Maybe +import Control.Monad +import Data.Map (Map) +import qualified Data.Map as Map import Outputable -import UniqSupply -import UniqFM -import UniqSet -import Unique - -import Monad -import IO -import Data.List +import StaticFlags ----------------------------------------------------------------------------- -- |Top level driver for the CPS pass ----------------------------------------------------------------------------- -cmmCPS :: DynFlags -- ^ Dynamic flags: -dcmm-lint -ddump-cps-cmm - -> [GenCmm CmmStatic CmmInfo CmmStmt] -- ^ Input C-- with Proceedures - -> IO [GenCmm CmmStatic [CmmStatic] CmmStmt] -- ^ Output CPS transformed C-- -cmmCPS dflags abstractC = do - when (dopt Opt_DoCmmLinting dflags) $ - do showPass dflags "CmmLint" - case firstJust $ map cmmLint abstractC of - Just err -> do printDump err - ghcExit dflags 1 - Nothing -> return () - showPass dflags "CPS" - - -- TODO: more lint checking - -- check for use of branches to non-existant blocks - -- check for use of Sp, SpLim, R1, R2, etc. - - uniqSupply <- mkSplitUniqSupply 'p' - let supplies = listSplitUniqSupply uniqSupply - let doCpsProc s (Cmm c) = - Cmm $ concat $ zipWith cpsProc (listSplitUniqSupply s) c - let continuationC = zipWith doCpsProc supplies abstractC - - dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "CPS Cmm" (pprCmms continuationC) - - -- TODO: add option to dump Cmm to file - - return continuationC - -stg_gc_gen = mkRtsApFastLabel SLIT("gen_cg_TODO") --panic "Need the label for gc" -make_gc_block block_id fun_label formals safety = BasicBlock block_id stmts - where - stmts = [CmmCall stg_gc_gen_target [] [] safety, - CmmJump fun_expr actuals] - stg_gc_gen_target = - CmmForeignCall (CmmLit (CmmLabel stg_gc_gen)) CmmCallConv - actuals = map (\x -> (CmmReg (CmmLocal x), NoHint)) formals - fun_expr = CmmLit (CmmLabel fun_label) - -force_gc_block old_info block_id fun_label formals blocks = - case old_info of - CmmNonInfo (Just _) -> (old_info, []) - CmmInfo _ (Just _) _ _ -> (old_info, []) - CmmNonInfo Nothing - -> (CmmNonInfo (Just block_id), - [make_gc_block block_id fun_label formals (CmmSafe NoC_SRT)]) - 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)]) - where - srt = case type_info of - ConstrInfo _ _ _ -> NoC_SRT - FunInfo _ srt' _ _ _ _ -> srt' - ThunkInfo _ srt' -> srt' - ThunkSelectorInfo _ srt' -> srt' - ContInfo _ srt' -> srt' - ------------------------------------------------------------------------------ --- |CPS a single CmmTop (proceedure) --- Only 'CmmProc' are transformed 'CmmData' will be left alone. ------------------------------------------------------------------------------ - -cpsProc :: UniqSupply - -> GenCmmTop CmmStatic CmmInfo CmmStmt -- ^Input proceedure - -> [GenCmmTop CmmStatic [CmmStatic] CmmStmt] -- ^Output proceedure and continuations -cpsProc uniqSupply (CmmData sec dat) = [CmmData sec dat] -cpsProc uniqSupply (CmmProc info ident params blocks) = info_procs - where - uniques :: [[Unique]] - uniques = map uniqsFromSupply $ listSplitUniqSupply uniqSupply - (gc_unique:info_uniques):block_uniques = uniques - - -- Ensure that - forced_gc :: (CmmInfo, [CmmBasicBlock]) - forced_gc = force_gc_block info (BlockId gc_unique) ident params blocks - - forced_info = fst forced_gc - forced_blocks = blocks ++ snd forced_gc - forced_gc_id = case forced_info of - CmmNonInfo (Just x) -> x - CmmInfo _ (Just x) _ _ -> x - - -- Break the block at each function call. - -- The part after the function call will have to become a continuation. - broken_blocks :: [BrokenBlock] - broken_blocks = - concat $ zipWith3 breakBlock block_uniques forced_blocks - (FunctionEntry forced_info ident params:repeat ControlEntry) - - -- Calculate live variables for each broken block. - -- - -- Nothing can be live on entry to the first block - -- so we could take the tail, but for now we wont - -- to help future proof the code. - live :: BlockEntryLiveness - live = cmmLiveness $ map cmmBlockFromBrokenBlock broken_blocks - - -- Calculate which blocks must be made into full fledged procedures. - proc_points :: UniqSet BlockId - proc_points = calculateProcPoints broken_blocks - - -- Construct a map so we can lookup a broken block by its 'BlockId'. - block_env :: BlockEnv BrokenBlock - block_env = blocksToBlockEnv broken_blocks - - -- Group the blocks into continuations based on the set of proc-points. - continuations :: [Continuation (Either C_SRT CmmInfo)] - continuations = zipWith - (gatherBlocksIntoContinuation proc_points block_env) - (uniqSetToList proc_points) - (Just forced_gc_id : repeat Nothing) - - -- 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 - (Maybe CLabel, -- label in top slot - [Maybe LocalReg]))] -- slots - formats = selectStackFormat live continuations - - -- Do a little meta-processing on the stack formats such as - -- getting the individual frame sizes and the maximum frame size - formats' :: (WordOff, [(CLabel, StackFormat)]) - formats' = processFormats formats continuations - - -- Update the info table data on the continuations with - -- the selected stack formats. - continuations' :: [Continuation CmmInfo] - continuations' = map (applyStackFormat (snd formats')) continuations - - -- Do the actual CPS transform. - cps_procs :: [CmmTop] - cps_procs = map (continuationToProc formats') 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) - [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 StackFormat - = StackFormat { - stack_label :: Maybe CLabel, -- The label occupying the top slot - stack_frame_size :: WordOff, -- Total frame size in words (not including arguments) - stack_live :: [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 :: - 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 - blocks' = map (lookupWithDefaultUFM blocks (panic "TODO")) new_blocks - targets = - -- Note the subtlety that since the extra branch after a call - -- will always be to a block that is a proc-point, - -- this subtraction will always remove that case - uniqSetToList $ (unionManyUniqSets $ map (mkUniqSet . brokenBlockTargets) blocks') - `minusUniqSet` proc_points - -- TODO: remove redundant uniqSetToList - new_targets = current_targets `unionUniqSets` (mkUniqSet targets) - --- 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 :: - UniqSet BlockId -> BlockEnv BrokenBlock - -> BlockId -> Maybe BlockId -> Continuation (Either C_SRT CmmInfo) -gatherBlocksIntoContinuation proc_points blocks start gc = - Continuation info_table clabel params 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) - start_block = lookupWithDefaultUFM blocks (panic "TODO") start - 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 - - -- We can't properly annotate the continuation's stack parameters - -- at this point because this is before stack selection - -- but we want to keep the C_SRT around so we use 'Either'. - info_table = case start_block_entry of - FunctionEntry info _ _ -> Right info - ContinuationEntry _ srt -> Left srt - ControlEntry -> Right (CmmNonInfo Nothing) - - 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 -> [] -- TODO: it's a proc-point, we could pass lives in parameter registers - --------------------------------------------------------------------------------- --- For now just select the continuation orders in the order they are in the set with no gaps - -selectStackFormat :: BlockEnv CmmLive - -> [Continuation (Either C_SRT CmmInfo)] - -> [(CLabel, (Maybe CLabel, [Maybe LocalReg]))] -selectStackFormat live continuations = - map (\c -> (continuationLabel c, selectStackFormat' c)) continuations - where - selectStackFormat' (Continuation - (Right (CmmInfo _ _ _ (ContInfo format srt))) - label _ _) = (Just label, format) - selectStackFormat' (Continuation (Right _) _ _ _) = (Nothing, []) - selectStackFormat' (Continuation (Left srt) label _ 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 (Just label, - map Just $ uniqSetToList $ - lookupWithDefaultUFM live unknown_block ident) - - unknown_block = panic "unknown BlockId in selectStackFormat" - -processFormats :: [(CLabel, (Maybe CLabel, [Maybe LocalReg]))] - -> [Continuation (Either C_SRT CmmInfo)] - -> (WordOff, [(CLabel, StackFormat)]) -processFormats formats continuations = (max_size, formats') - where - max_size = maximum $ - 0 : map (continuationMaxStack formats') continuations - formats' = map make_format formats - make_format (label, format) = - (label, - StackFormat { - stack_label = fst format, - stack_frame_size = stack_size (snd format) + - if isJust (fst format) - then label_size - else 0, - stack_live = snd format }) - - -- TODO: get rid of "+ 1" etc. - label_size = 1 :: WordOff - - stack_size [] = 0 - stack_size (Nothing:formats) = 1 + stack_size formats -- one dead word - stack_size (Just reg:formats) = width + stack_size formats - where - width = machRepByteWidth (localRegRep reg) `quot` wORD_SIZE - -- TODO: it would be better if we had a machRepWordWidth - -continuationMaxStack :: [(CLabel, StackFormat)] - -> Continuation a - -> WordOff -continuationMaxStack formats (Continuation _ label _ blocks) = - max_arg_size + stack_frame_size stack_format - where - stack_format = maybe unknown_format id $ lookup label formats - unknown_format = panic "Unknown format in continuationMaxStack" - - max_arg_size = maximum $ 0 : map block_max_arg_size blocks - - block_max_arg_size block = - maximum (final_arg_size (brokenBlockExit block) : - map stmt_arg_size (brokenBlockStmts block)) - - final_arg_size (FinalReturn args) = - argumentsSize (cmmExprRep . fst) args - final_arg_size (FinalJump _ args) = - argumentsSize (cmmExprRep . fst) args - final_arg_size (FinalCall next _ _ args) = - -- We have to account for the stack used when we build a frame - -- for the *next* continuation from *this* continuation - argumentsSize (cmmExprRep . fst) args + - stack_frame_size next_format - where - next_format = maybe unknown_format id $ lookup next' formats - next' = mkReturnPtLabel $ getUnique next - - final_arg_size _ = 0 - - stmt_arg_size (CmmJump _ args) = - argumentsSize (cmmExprRep . fst) args - stmt_arg_size (CmmCall _ _ _ (CmmSafe _)) = - panic "Safe call in processFormats" - stmt_arg_size (CmmReturn _) = - panic "CmmReturn in processFormats" - stmt_arg_size _ = 0 - ------------------------------------------------------------------------------ -applyStackFormat :: [(CLabel, StackFormat)] - -> Continuation (Either C_SRT CmmInfo) - -> Continuation CmmInfo - --- User written continuations -applyStackFormat formats (Continuation - (Right (CmmInfo prof gc tag (ContInfo _ srt))) - label formals blocks) = - Continuation (CmmInfo prof gc tag (ContInfo format srt)) - label formals blocks - where - format = stack_live $ maybe unknown_block id $ lookup label formats - unknown_block = panic "unknown BlockId in applyStackFormat" - --- User written non-continuation code -applyStackFormat formats (Continuation (Right info) label formals blocks) = - Continuation info label formals blocks - --- CPS generated continuations -applyStackFormat formats (Continuation (Left srt) label formals blocks) = - Continuation (CmmInfo prof gc tag (ContInfo (stack_live $ format) srt)) - label formals 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 applyStackFormat" - ------------------------------------------------------------------------------ -continuationToProc :: (WordOff, [(CLabel, StackFormat)]) - -> Continuation CmmInfo - -> CmmTop -continuationToProc (max_stack, formats) - (Continuation info label formals blocks) = - CmmProc info label formals (map continuationToProc' blocks) - where - curr_format = maybe unknown_block id $ lookup label formats - unknown_block = panic "unknown BlockId in continuationToProc" - - continuationToProc' :: BrokenBlock -> CmmBasicBlock - continuationToProc' (BrokenBlock ident entry stmts _ exit) = - BasicBlock ident (prefix++stmts++postfix) - where - prefix = case entry of - ControlEntry -> [] - FunctionEntry (CmmInfo _ (Just gc_block) _ _) _ formals -> - gc_stack_check gc_block max_stack ++ - function_entry formals curr_format - FunctionEntry (CmmInfo _ Nothing _ _) _ formals -> - panic "continuationToProc: missing GC block" - FunctionEntry (CmmNonInfo (Just gc_block)) _ formals -> - gc_stack_check gc_block max_stack ++ - function_entry formals curr_format - FunctionEntry (CmmNonInfo Nothing) _ formals -> - panic "continuationToProc: missing non-info GC block" - ContinuationEntry formals _ -> - function_entry formals curr_format - postfix = case exit of - FinalBranch next -> [CmmBranch next] - FinalSwitch expr targets -> [CmmSwitch expr targets] - FinalReturn arguments -> - tail_call (stack_frame_size curr_format) - (CmmLoad (CmmReg spReg) wordRep) - arguments - FinalJump target arguments -> - tail_call (stack_frame_size curr_format) target arguments - FinalCall next (CmmForeignCall target CmmCallConv) - results arguments -> - pack_continuation curr_format cont_format ++ - tail_call (stack_frame_size curr_format - stack_frame_size cont_format) - target arguments - where - cont_format = maybe unknown_block id $ - lookup (mkReturnPtLabel $ getUnique next) formats - 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 :: 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 :: StackFormat -> StackFormat -> [CmmStmt] -pack_continuation (StackFormat curr_id curr_frame_size _) - (StackFormat 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 - 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 :: CmmFormals -> StackFormat -> [CmmStmt] -function_entry formals (StackFormat _ _ 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)) - +-- There are two complications here: +-- 1. We need to compile the procedures in two stages because we need +-- an analysis of the procedures to tell us what CAFs they use. +-- The first stage returns a map from procedure labels to CAFs, +-- along with a closure that will compute SRTs and attach them to +-- the compiled procedures. +-- The second stage is to combine the CAF information into a top-level +-- CAF environment mapping non-static closures to the CAFs they keep live, +-- then pass that environment to the closures returned in the first +-- stage of compilation. +-- 2. We need to thread the module's SRT around when the SRT tables +-- are computed for each procedure. +-- The SRT needs to be threaded because it is grown lazily. +protoCmmCPS :: HscEnv -- Compilation env including + -- dynamic flags: -dcmm-lint -ddump-cps-cmm + -> (TopSRT, [Cmm]) -- SRT table and accumulating list of compiled procs + -> Cmm -- Input C-- with Procedures + -> IO (TopSRT, [Cmm]) -- Output CPS transformed C-- +protoCmmCPS hsc_env (topSRT, rst) (Cmm tops) = + do let dflags = hsc_dflags hsc_env + showPass dflags "CPSZ" + (cafEnvs, tops) <- liftM unzip $ mapM (cpsTop hsc_env) tops + let topCAFEnv = mkTopCAFInfo (concat cafEnvs) + (topSRT, tops) <- foldM (toTops hsc_env topCAFEnv) (topSRT, []) tops + let cmms = Cmm (reverse (concat tops)) + dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "Post CPS Cmm" (ppr cmms) + return (topSRT, cmms : rst) + +{- [Note global fuel] +~~~~~~~~~~~~~~~~~~~~~ +The identity and the last pass are stored in +mutable reference cells in an 'HscEnv' and are +global to one compiler session. +-} + +-- EZY: It might be helpful to have an easy way of dumping the "pre" +-- input for any given phase, besides just turning it all on with +-- -ddump-cmmz + +cpsTop :: HscEnv -> CmmTop -> IO ([(CLabel, CAFSet)], [(CAFSet, CmmTop)]) +cpsTop _ p@(CmmData {}) = return ([], [(Map.empty, p)]) +cpsTop hsc_env (CmmProc h@(TopInfo {stack_info=StackInfo {arg_space=entry_off}}) l g) = + do + -- Why bother doing these early: dualLivenessWithInsertion, + -- insertLateReloads, rewriteAssignments? + + ----------- Eliminate common blocks ------------------- + g <- return $ elimCommonBlocks g + dump Opt_D_dump_cmmz_cbe "Post common block elimination" g + -- Any work storing block Labels must be performed _after_ elimCommonBlocks + + ----------- Proc points ------------------- + let callPPs = callProcPoints g + procPoints <- run $ minimalProcPointSet callPPs g + g <- run $ addProcPointProtocols callPPs procPoints g + dump Opt_D_dump_cmmz_proc "Post Proc Points Added" g + + ----------- Spills and reloads ------------------- + g <- run $ dualLivenessWithInsertion procPoints g + dump Opt_D_dump_cmmz_spills "Post spills and reloads" g + + ----------- Sink and inline assignments ------------------- + g <- runOptimization $ rewriteAssignments g + dump Opt_D_dump_cmmz_rewrite "Post rewrite assignments" g + + ----------- Eliminate dead assignments ------------------- + -- Remove redundant reloads (and any other redundant asst) + g <- runOptimization $ removeDeadAssignmentsAndReloads procPoints g + dump Opt_D_dump_cmmz_dead "Post Dead Assignment Elimination" g + + ----------- Zero dead stack slots (Debug only) --------------- + -- Debugging: stubbing slots on death can cause crashes early + g <- if opt_StubDeadValues + then run $ stubSlotsOnDeath g + else return g + dump Opt_D_dump_cmmz_stub "Post stub dead stack slots" g + + --------------- Stack layout ---------------- + slotEnv <- run $ liveSlotAnal g + let spEntryMap = getSpEntryMap entry_off g + mbpprTrace "live slot analysis results: " (ppr slotEnv) $ return () + let areaMap = layout procPoints spEntryMap slotEnv entry_off g + mbpprTrace "areaMap" (ppr areaMap) $ return () + + ------------ Manifest the stack pointer -------- + g <- run $ manifestSP spEntryMap areaMap entry_off g + dump Opt_D_dump_cmmz_sp "Post manifestSP" g + -- UGH... manifestSP can require updates to the procPointMap. + -- We can probably do something quicker here for the update... + + ------------- Split into separate procedures ------------ + procPointMap <- run $ procPointAnalysis procPoints g + dump Opt_D_dump_cmmz_procmap "procpoint map" procPointMap + gs <- run $ splitAtProcPoints l callPPs procPoints procPointMap + (CmmProc h l g) + mapM_ (dump Opt_D_dump_cmmz_split "Post splitting") gs + + ------------- More CAFs and foreign calls ------------ + cafEnv <- run $ cafAnal g + let localCAFs = catMaybes $ map (localCAFInfo cafEnv) gs + mbpprTrace "localCAFs" (ppr localCAFs) $ return () + + gs <- run $ mapM (lowerSafeForeignCalls areaMap) gs + mapM_ (dump Opt_D_dump_cmmz_lower "Post lowerSafeForeignCalls") gs + + -- NO MORE GRAPH TRANSFORMATION AFTER HERE -- JUST MAKING INFOTABLES + gs <- return $ map (setInfoTableStackMap slotEnv areaMap) gs + mapM_ (dump Opt_D_dump_cmmz_info "after setInfoTableStackMap") gs + gs <- return $ map (bundleCAFs cafEnv) gs + mapM_ (dump Opt_D_dump_cmmz_cafs "after bundleCAFs") gs + return (localCAFs, gs) + where dflags = hsc_dflags hsc_env + mbpprTrace x y z = if dopt Opt_D_dump_cmmz dflags then pprTrace x y z else z + dump f txt g = do + -- ToDo: No easy way of say "dump all the cmmz, *and* split + -- them into files." Also, -ddump-cmmz doesn't play nicely + -- with -ddump-to-file, since the headers get omitted. + dumpIfSet_dyn dflags f txt (ppr g) + when (not (dopt f dflags)) $ + dumpIfSet_dyn dflags Opt_D_dump_cmmz txt (ppr g) + -- Runs a required transformation/analysis + run = runInfiniteFuelIO (hsc_OptFuel hsc_env) + -- Runs an optional transformation/analysis (and should + -- thus be subject to optimization fuel) + runOptimization = runFuelIO (hsc_OptFuel hsc_env) + +-- This probably belongs in CmmBuildInfoTables? +-- We're just finishing the job here: once we know what CAFs are defined +-- in non-static closures, we can build the SRTs. +toTops :: HscEnv -> Map CLabel CAFSet -> (TopSRT, [[CmmTop]]) + -> [(CAFSet, CmmTop)] -> IO (TopSRT, [[CmmTop]]) +toTops hsc_env topCAFEnv (topSRT, tops) gs = + do let setSRT (topSRT, rst) g = + do (topSRT, gs) <- setInfoTableSRT topCAFEnv topSRT g + return (topSRT, gs : rst) + (topSRT, gs') <- runFuelIO (hsc_OptFuel hsc_env) $ foldM setSRT (topSRT, []) gs + return (topSRT, concat gs' : tops)