----------------------------------------------------------------------------- -- -- Code generation for foreign calls. -- -- (c) The University of Glasgow 2004-2006 -- ----------------------------------------------------------------------------- module StgCmmForeign ( cgForeignCall, loadThreadState, saveThreadState, emitPrimCall, emitCCall, emitSaveThreadState, -- will be needed by the Cmm parser emitLoadThreadState, -- ditto emitOpenNursery, ) where #include "HsVersions.h" import StgSyn import StgCmmProf import StgCmmEnv import StgCmmMonad import StgCmmUtils import StgCmmClosure import BlockId import Cmm import CmmUtils import MkZipCfgCmm hiding (CmmAGraph) import Type import TysPrim import CLabel import SMRep import ForeignCall import Constants import StaticFlags import Maybes import Outputable import ZipCfgCmmRep import BasicTypes import Control.Monad ----------------------------------------------------------------------------- -- Code generation for Foreign Calls ----------------------------------------------------------------------------- cgForeignCall :: [LocalReg] -- r1,r2 where to put the results -> [ForeignHint] -> ForeignCall -- the op -> [StgArg] -- x,y arguments -> FCode () -- Emits code for an unsafe foreign call: r1, r2 = foo( x, y, z ) cgForeignCall results result_hints (CCall (CCallSpec target cconv safety)) stg_args = do { cmm_args <- getFCallArgs stg_args ; let ((call_args, arg_hints), cmm_target) = case target of StaticTarget lbl -> (unzip cmm_args, CmmLit (CmmLabel (mkForeignLabel lbl (call_size cmm_args) False IsFunction))) DynamicTarget -> case cmm_args of (fn,_):rest -> (unzip rest, fn) [] -> panic "cgForeignCall []" fc = ForeignConvention cconv arg_hints result_hints call_target = ForeignTarget cmm_target fc ; srt <- getSRTInfo NoSRT -- SLPJ: Not sure what SRT -- is right here -- JD: Does it matter in the new codegen? ; emitForeignCall safety results call_target call_args srt CmmMayReturn } where -- in the stdcall calling convention, the symbol needs @size appended -- to it, where size is the total number of bytes of arguments. We -- attach this info to the CLabel here, and the CLabel pretty printer -- will generate the suffix when the label is printed. call_size args | StdCallConv <- cconv = Just (sum (map arg_size args)) | otherwise = Nothing -- ToDo: this might not be correct for 64-bit API arg_size (arg, _) = max (widthInBytes $ typeWidth $ cmmExprType arg) wORD_SIZE emitCCall :: [(CmmFormal,ForeignHint)] -> CmmExpr -> [(CmmActual,ForeignHint)] -> FCode () emitCCall hinted_results fn hinted_args = emitForeignCall PlayRisky results target args NoC_SRT -- No SRT b/c we PlayRisky CmmMayReturn where (args, arg_hints) = unzip hinted_args (results, result_hints) = unzip hinted_results target = ForeignTarget fn fc fc = ForeignConvention CCallConv arg_hints result_hints emitPrimCall :: CmmFormal -> CallishMachOp -> CmmActuals -> FCode () emitPrimCall res op args = emitForeignCall PlayRisky [res] (PrimTarget op) args NoC_SRT CmmMayReturn -- alternative entry point, used by CmmParse emitForeignCall :: Safety -> CmmFormals -- where to put the results -> MidCallTarget -- the op -> CmmActuals -- arguments -> C_SRT -- the SRT of the calls continuation -> CmmReturnInfo -- This can say "never returns" -- only RTS procedures do this -> FCode () emitForeignCall safety results target args _srt _ret | not (playSafe safety) = do let (caller_save, caller_load) = callerSaveVolatileRegs emit caller_save emit $ mkUnsafeCall target results args emit caller_load | otherwise = do updfr_off <- getUpdFrameOff temp_target <- load_target_into_temp target emit $ mkSafeCall temp_target results args updfr_off {- -- THINK ABOUT THIS (used to happen) -- we might need to load arguments into temporaries before -- making the call, because certain global registers might -- overlap with registers that the C calling convention uses -- for passing arguments. -- -- This is a HACK; really it should be done in the back end, but -- it's easier to generate the temporaries here. load_args_into_temps = mapM arg_assign_temp where arg_assign_temp (e,hint) = do tmp <- maybe_assign_temp e return (tmp,hint) -} load_target_into_temp :: MidCallTarget -> FCode MidCallTarget load_target_into_temp (ForeignTarget expr conv) = do tmp <- maybe_assign_temp expr return (ForeignTarget tmp conv) load_target_into_temp other_target@(PrimTarget _) = return other_target maybe_assign_temp :: CmmExpr -> FCode CmmExpr maybe_assign_temp e | hasNoGlobalRegs e = return e | otherwise = do -- don't use assignTemp, it uses its own notion of "trivial" -- expressions, which are wrong here. -- this is a NonPtr because it only duplicates an existing reg <- newTemp (cmmExprType e) --TODO FIXME NOW emit (mkAssign (CmmLocal reg) e) return (CmmReg (CmmLocal reg)) -- ----------------------------------------------------------------------------- -- Save/restore the thread state in the TSO -- This stuff can't be done in suspendThread/resumeThread, because it -- refers to global registers which aren't available in the C world. saveThreadState :: CmmAGraph saveThreadState = -- CurrentTSO->sp = Sp; mkStore (cmmOffset stgCurrentTSO tso_SP) stgSp <*> closeNursery -- and save the current cost centre stack in the TSO when profiling: <*> if opt_SccProfilingOn then mkStore (cmmOffset stgCurrentTSO tso_CCCS) curCCS else mkNop emitSaveThreadState :: BlockId -> FCode () emitSaveThreadState bid = do -- CurrentTSO->sp = Sp; emit $ mkStore (cmmOffset stgCurrentTSO tso_SP) (CmmStackSlot (CallArea (Young bid)) (widthInBytes (typeWidth gcWord))) emit closeNursery -- and save the current cost centre stack in the TSO when profiling: when opt_SccProfilingOn $ emit (mkStore (cmmOffset stgCurrentTSO tso_CCCS) curCCS) -- CurrentNursery->free = Hp+1; closeNursery :: CmmAGraph closeNursery = mkStore nursery_bdescr_free (cmmOffsetW stgHp 1) loadThreadState :: LocalReg -> CmmAGraph loadThreadState tso = do -- tso <- newTemp gcWord -- TODO FIXME NOW catAGraphs [ -- tso = CurrentTSO; mkAssign (CmmLocal tso) stgCurrentTSO, -- Sp = tso->sp; mkAssign sp (CmmLoad (cmmOffset (CmmReg (CmmLocal tso)) tso_SP) bWord), -- SpLim = tso->stack + RESERVED_STACK_WORDS; mkAssign 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 mkStore curCCSAddr (CmmLoad (cmmOffset (CmmReg (CmmLocal tso)) tso_CCCS) ccsType) else mkNop] emitLoadThreadState :: LocalReg -> FCode () emitLoadThreadState tso = emit $ loadThreadState tso openNursery :: CmmAGraph openNursery = catAGraphs [ -- Hp = CurrentNursery->free - 1; mkAssign hp (cmmOffsetW (CmmLoad nursery_bdescr_free bWord) (-1)), -- HpLim = CurrentNursery->start + -- CurrentNursery->blocks*BLOCK_SIZE_W - 1; mkAssign hpLim (cmmOffsetExpr (CmmLoad nursery_bdescr_start bWord) (cmmOffset (CmmMachOp mo_wordMul [ CmmMachOp (MO_SS_Conv W32 wordWidth) [CmmLoad nursery_bdescr_blocks b32], CmmLit (mkIntCLit bLOCK_SIZE) ]) (-1) ) ) ] emitOpenNursery :: FCode () emitOpenNursery = emit openNursery nursery_bdescr_free, nursery_bdescr_start, nursery_bdescr_blocks :: CmmExpr 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, tso_STACK, tso_CCCS :: ByteOff 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, stgHp, stgCurrentTSO, stgCurrentNursery :: CmmExpr stgSp = CmmReg sp stgHp = CmmReg hp stgCurrentTSO = CmmReg currentTSO stgCurrentNursery = CmmReg currentNursery sp, spLim, hp, hpLim, currentTSO, currentNursery :: CmmReg sp = CmmGlobal Sp spLim = CmmGlobal SpLim hp = CmmGlobal Hp hpLim = CmmGlobal HpLim currentTSO = CmmGlobal CurrentTSO currentNursery = CmmGlobal CurrentNursery -- ----------------------------------------------------------------------------- -- For certain types passed to foreign calls, we adjust the actual -- value passed to the call. For ByteArray#/Array# we pass the -- address of the actual array, not the address of the heap object. getFCallArgs :: [StgArg] -> FCode [(CmmExpr, ForeignHint)] -- (a) Drop void args -- (b) Add foreign-call shim code -- It's (b) that makes this differ from getNonVoidArgAmodes getFCallArgs args = do { mb_cmms <- mapM get args ; return (catMaybes mb_cmms) } where get arg | isVoidRep arg_rep = return Nothing | otherwise = do { cmm <- getArgAmode (NonVoid arg) ; return (Just (add_shim arg_ty cmm, hint)) } where arg_ty = stgArgType arg arg_rep = typePrimRep arg_ty hint = typeForeignHint arg_ty add_shim :: Type -> CmmExpr -> CmmExpr add_shim arg_ty expr | tycon == arrayPrimTyCon || tycon == mutableArrayPrimTyCon = cmmOffsetB expr arrPtrsHdrSize | tycon == byteArrayPrimTyCon || tycon == mutableByteArrayPrimTyCon = cmmOffsetB expr arrWordsHdrSize | otherwise = expr where tycon = tyConAppTyCon (repType arg_ty) -- should be a tycon app, since this is a foreign call