{-# 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. -- Well, sort of. protoCmmCPS ) where import CLabel import Cmm import CmmDecl import CmmBuildInfoTables import CmmCommonBlockElim import CmmProcPoint import CmmSpillReload import CmmStackLayout import OptimizationFuel import DynFlags import ErrUtils import HscTypes import Data.Maybe import Control.Monad import Data.Map (Map) import qualified Data.Map as Map import Outputable import StaticFlags ----------------------------------------------------------------------------- -- |Top level driver for the CPS pass ----------------------------------------------------------------------------- -- 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)