----------------------------------------------------------------------------- -- -- Code generation for profiling -- -- (c) The University of Glasgow 2004-2006 -- ----------------------------------------------------------------------------- module GHC.StgToCmm.Prof ( initCostCentres, ccType, ccsType, mkCCostCentre, mkCCostCentreStack, -- infoTablePRov initInfoTableProv, emitInfoTableProv, -- Cost-centre Profiling dynProfHdr, profDynAlloc, profAlloc, staticProfHdr, initUpdFrameProf, enterCostCentreThunk, enterCostCentreFun, costCentreFrom, storeCurCCS, emitSetCCC, saveCurrentCostCentre, restoreCurrentCostCentre, -- Lag/drag/void stuff ldvEnter, ldvEnterClosure, ldvRecordCreate ) where import GHC.Prelude import GHC.Driver.Session import GHC.Driver.Ppr import GHC.Platform import GHC.Platform.Profile import GHC.StgToCmm.Closure import GHC.StgToCmm.Utils import GHC.StgToCmm.Monad import GHC.Runtime.Heap.Layout import GHC.Cmm.Graph import GHC.Cmm import GHC.Cmm.Utils import GHC.Cmm.CLabel import GHC.Types.CostCentre import GHC.Types.IPE import GHC.Types.ForeignStubs import GHC.Data.FastString import GHC.Unit.Module as Module import GHC.Utils.Outputable import GHC.Utils.Panic import GHC.Driver.CodeOutput ( ipInitCode ) import GHC.Utils.Encoding import Control.Monad import Data.Char (ord) ----------------------------------------------------------------------------- -- -- Cost-centre-stack Profiling -- ----------------------------------------------------------------------------- -- Expression representing the current cost centre stack ccsType :: Platform -> CmmType -- Type of a cost-centre stack ccsType = bWord ccType :: Platform -> CmmType -- Type of a cost centre ccType = bWord storeCurCCS :: CmmExpr -> CmmAGraph storeCurCCS e = mkAssign cccsReg e mkCCostCentre :: CostCentre -> CmmLit mkCCostCentre cc = CmmLabel (mkCCLabel cc) mkCCostCentreStack :: CostCentreStack -> CmmLit mkCCostCentreStack ccs = CmmLabel (mkCCSLabel ccs) costCentreFrom :: Platform -> CmmExpr -- A closure pointer -> CmmExpr -- The cost centre from that closure costCentreFrom platform cl = CmmLoad (cmmOffsetB platform cl (pc_OFFSET_StgHeader_ccs (platformConstants platform))) (ccsType platform) -- | The profiling header words in a static closure staticProfHdr :: Profile -> CostCentreStack -> [CmmLit] staticProfHdr profile ccs | profileIsProfiling profile = [mkCCostCentreStack ccs, staticLdvInit platform] | otherwise = [] where platform = profilePlatform profile -- | Profiling header words in a dynamic closure dynProfHdr :: Profile -> CmmExpr -> [CmmExpr] dynProfHdr profile ccs | profileIsProfiling profile = [ccs, dynLdvInit (profilePlatform profile)] | otherwise = [] -- | Initialise the profiling field of an update frame initUpdFrameProf :: CmmExpr -> FCode () initUpdFrameProf frame = ifProfiling $ -- frame->header.prof.ccs = CCCS do platform <- getPlatform emitStore (cmmOffset platform frame (pc_OFFSET_StgHeader_ccs (platformConstants platform))) cccsExpr -- frame->header.prof.hp.rs = NULL (or frame-header.prof.hp.ldvw = 0) -- is unnecessary because it is not used anyhow. --------------------------------------------------------------------------- -- Saving and restoring the current cost centre --------------------------------------------------------------------------- {- Note [Saving the current cost centre] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The current cost centre is like a global register. Like other global registers, it's a caller-saves one. But consider case (f x) of (p,q) -> rhs Since 'f' may set the cost centre, we must restore it before resuming rhs. So we want code like this: local_cc = CCC -- save r = f( x ) CCC = local_cc -- restore That is, we explicitly "save" the current cost centre in a LocalReg, local_cc; and restore it after the call. The C-- infrastructure will arrange to save local_cc across the call. The same goes for join points; let j x = join-stuff in blah-blah We want this kind of code: local_cc = CCC -- save blah-blah J: CCC = local_cc -- restore -} saveCurrentCostCentre :: FCode (Maybe LocalReg) -- Returns Nothing if profiling is off saveCurrentCostCentre = do dflags <- getDynFlags platform <- getPlatform if not (sccProfilingEnabled dflags) then return Nothing else do local_cc <- newTemp (ccType platform) emitAssign (CmmLocal local_cc) cccsExpr return (Just local_cc) restoreCurrentCostCentre :: Maybe LocalReg -> FCode () restoreCurrentCostCentre Nothing = return () restoreCurrentCostCentre (Just local_cc) = emit (storeCurCCS (CmmReg (CmmLocal local_cc))) ------------------------------------------------------------------------------- -- Recording allocation in a cost centre ------------------------------------------------------------------------------- -- | Record the allocation of a closure. The CmmExpr is the cost -- centre stack to which to attribute the allocation. profDynAlloc :: SMRep -> CmmExpr -> FCode () profDynAlloc rep ccs = ifProfiling $ do profile <- targetProfile <$> getDynFlags let platform = profilePlatform profile profAlloc (mkIntExpr platform (heapClosureSizeW profile rep)) ccs -- | Record the allocation of a closure (size is given by a CmmExpr) -- The size must be in words, because the allocation counter in a CCS counts -- in words. profAlloc :: CmmExpr -> CmmExpr -> FCode () profAlloc words ccs = ifProfiling $ do profile <- targetProfile <$> getDynFlags let platform = profilePlatform profile let alloc_rep = rEP_CostCentreStack_mem_alloc platform emit $ addToMemE alloc_rep (cmmOffsetB platform ccs (pc_OFFSET_CostCentreStack_mem_alloc (platformConstants platform))) (CmmMachOp (MO_UU_Conv (wordWidth platform) (typeWidth alloc_rep)) $ -- subtract the "profiling overhead", which is the -- profiling header in a closure. [CmmMachOp (mo_wordSub platform) [ words, mkIntExpr platform (profHdrSize profile)]] ) -- ----------------------------------------------------------------------- -- Setting the current cost centre on entry to a closure enterCostCentreThunk :: CmmExpr -> FCode () enterCostCentreThunk closure = ifProfiling $ do platform <- getPlatform emit $ storeCurCCS (costCentreFrom platform closure) enterCostCentreFun :: CostCentreStack -> CmmExpr -> FCode () enterCostCentreFun ccs closure = ifProfiling $ if isCurrentCCS ccs then do platform <- getPlatform emitRtsCall rtsUnitId (fsLit "enterFunCCS") [(baseExpr, AddrHint), (costCentreFrom platform closure, AddrHint)] False else return () -- top-level function, nothing to do ifProfiling :: FCode () -> FCode () ifProfiling code = do profile <- targetProfile <$> getDynFlags if profileIsProfiling profile then code else return () --------------------------------------------------------------- -- Initialising Cost Centres & CCSs --------------------------------------------------------------- initCostCentres :: CollectedCCs -> FCode () -- Emit the declarations initCostCentres (local_CCs, singleton_CCSs) = ifProfiling $ do mapM_ emitCostCentreDecl local_CCs mapM_ emitCostCentreStackDecl singleton_CCSs emitCostCentreDecl :: CostCentre -> FCode () emitCostCentreDecl cc = do { dflags <- getDynFlags ; platform <- getPlatform ; let is_caf | isCafCC cc = mkIntCLit platform (ord 'c') -- 'c' == is a CAF | otherwise = zero platform -- NB. bytesFS: we want the UTF-8 bytes here (#5559) ; label <- newByteStringCLit (bytesFS $ costCentreUserNameFS cc) ; modl <- newByteStringCLit (bytesFS $ moduleNameFS $ moduleName $ cc_mod cc) ; loc <- newByteStringCLit $ utf8EncodeString $ showPpr dflags (costCentreSrcSpan cc) ; let lits = [ zero platform, -- StgInt ccID, label, -- char *label, modl, -- char *module, loc, -- char *srcloc, zero64, -- StgWord64 mem_alloc zero platform, -- StgWord time_ticks is_caf, -- StgInt is_caf zero platform -- struct _CostCentre *link ] ; emitDataLits (mkCCLabel cc) lits } emitCostCentreStackDecl :: CostCentreStack -> FCode () emitCostCentreStackDecl ccs = case maybeSingletonCCS ccs of Just cc -> do platform <- getPlatform let mk_lits cc = zero platform : mkCCostCentre cc : replicate (sizeof_ccs_words platform - 2) (zero platform) -- Note: to avoid making any assumptions about how the -- C compiler (that compiles the RTS, in particular) does -- layouts of structs containing long-longs, simply -- pad out the struct with zero words until we hit the -- size of the overall struct (which we get via DerivedConstants.h) emitDataLits (mkCCSLabel ccs) (mk_lits cc) Nothing -> pprPanic "emitCostCentreStackDecl" (ppr ccs) zero :: Platform -> CmmLit zero platform = mkIntCLit platform 0 zero64 :: CmmLit zero64 = CmmInt 0 W64 sizeof_ccs_words :: Platform -> Int sizeof_ccs_words platform -- round up to the next word. | ms == 0 = ws | otherwise = ws + 1 where (ws,ms) = pc_SIZEOF_CostCentreStack (platformConstants platform) `divMod` platformWordSizeInBytes platform initInfoTableProv :: [CmmInfoTable] -> InfoTableProvMap -> Module -> FCode CStub -- Emit the declarations initInfoTableProv infos itmap this_mod = do dflags <- getDynFlags let ents = convertInfoProvMap dflags infos this_mod itmap --pprTraceM "UsedInfo" (ppr (length infos)) --pprTraceM "initInfoTable" (ppr (length ents)) -- Output the actual IPE data mapM_ emitInfoTableProv ents -- Create the C stub which initialises the IPE_LIST return (ipInitCode dflags this_mod ents) --- Info Table Prov stuff emitInfoTableProv :: InfoProvEnt -> FCode () emitInfoTableProv ip = do { dflags <- getDynFlags ; let mod = infoProvModule ip ; let (src, label) = maybe ("", "") (\(s, l) -> (showPpr dflags s, l)) (infoTableProv ip) ; platform <- getPlatform ; let mk_string = newByteStringCLit . utf8EncodeString ; label <- mk_string label ; modl <- newByteStringCLit (bytesFS $ moduleNameFS $ moduleName $ mod) ; ty_string <- mk_string (infoTableType ip) ; loc <- mk_string src ; table_name <- mk_string (showPpr dflags (pprCLabel platform CStyle (infoTablePtr ip))) ; closure_type <- mk_string (showPpr dflags (text $ show $ infoProvEntClosureType ip)) ; let lits = [ CmmLabel (infoTablePtr ip), -- Info table pointer table_name, -- char *table_name closure_type, -- char *closure_desc -- Filled in from the InfoTable ty_string, -- char *ty_string label, -- char *label, modl, -- char *module, loc, -- char *srcloc, zero platform -- struct _InfoProvEnt *link ] ; emitDataLits (mkIPELabel ip) lits } -- --------------------------------------------------------------------------- -- Set the current cost centre stack emitSetCCC :: CostCentre -> Bool -> Bool -> FCode () emitSetCCC cc tick push = do profile <- targetProfile <$> getDynFlags let platform = profilePlatform profile if not (profileIsProfiling profile) then return () else do tmp <- newTemp (ccsType platform) pushCostCentre tmp cccsExpr cc when tick $ emit (bumpSccCount platform (CmmReg (CmmLocal tmp))) when push $ emit (storeCurCCS (CmmReg (CmmLocal tmp))) pushCostCentre :: LocalReg -> CmmExpr -> CostCentre -> FCode () pushCostCentre result ccs cc = emitRtsCallWithResult result AddrHint rtsUnitId (fsLit "pushCostCentre") [(ccs,AddrHint), (CmmLit (mkCCostCentre cc), AddrHint)] False bumpSccCount :: Platform -> CmmExpr -> CmmAGraph bumpSccCount platform ccs = addToMem (rEP_CostCentreStack_scc_count platform) (cmmOffsetB platform ccs (pc_OFFSET_CostCentreStack_scc_count (platformConstants platform))) 1 ----------------------------------------------------------------------------- -- -- Lag/drag/void stuff -- ----------------------------------------------------------------------------- -- -- Initial value for the LDV field in a static closure -- staticLdvInit :: Platform -> CmmLit staticLdvInit = zeroCLit -- -- Initial value of the LDV field in a dynamic closure -- dynLdvInit :: Platform -> CmmExpr dynLdvInit platform = -- (era << LDV_SHIFT) | LDV_STATE_CREATE CmmMachOp (mo_wordOr platform) [ CmmMachOp (mo_wordShl platform) [loadEra platform, mkIntExpr platform (pc_LDV_SHIFT (platformConstants platform))], CmmLit (mkWordCLit platform (pc_ILDV_STATE_CREATE (platformConstants platform))) ] -- -- Initialise the LDV word of a new closure -- ldvRecordCreate :: CmmExpr -> FCode () ldvRecordCreate closure = do platform <- getPlatform emit $ mkStore (ldvWord platform closure) (dynLdvInit platform) -- -- | Called when a closure is entered, marks the closure as having -- been "used". The closure is not an "inherently used" one. The -- closure is not @IND@ because that is not considered for LDV profiling. -- ldvEnterClosure :: ClosureInfo -> CmmReg -> FCode () ldvEnterClosure closure_info node_reg = do platform <- getPlatform let tag = funTag platform closure_info -- don't forget to subtract node's tag ldvEnter (cmmOffsetB platform (CmmReg node_reg) (-tag)) ldvEnter :: CmmExpr -> FCode () -- Argument is a closure pointer ldvEnter cl_ptr = do platform <- getPlatform let constants = platformConstants platform -- don't forget to subtract node's tag ldv_wd = ldvWord platform cl_ptr new_ldv_wd = cmmOrWord platform (cmmAndWord platform (CmmLoad ldv_wd (bWord platform)) (CmmLit (mkWordCLit platform (pc_ILDV_CREATE_MASK constants)))) (cmmOrWord platform (loadEra platform) (CmmLit (mkWordCLit platform (pc_ILDV_STATE_USE constants)))) ifProfiling $ -- if (era > 0) { -- LDVW((c)) = (LDVW((c)) & LDV_CREATE_MASK) | -- era | LDV_STATE_USE } emit =<< mkCmmIfThenElse (CmmMachOp (mo_wordUGt platform) [loadEra platform, CmmLit (zeroCLit platform)]) (mkStore ldv_wd new_ldv_wd) mkNop loadEra :: Platform -> CmmExpr loadEra platform = CmmMachOp (MO_UU_Conv (cIntWidth platform) (wordWidth platform)) [CmmLoad (mkLblExpr (mkRtsCmmDataLabel (fsLit "era"))) (cInt platform)] -- | Takes the address of a closure, and returns -- the address of the LDV word in the closure ldvWord :: Platform -> CmmExpr -> CmmExpr ldvWord platform closure_ptr = cmmOffsetB platform closure_ptr (pc_OFFSET_StgHeader_ldvw (platformConstants platform))