X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FcodeGen%2FCgRetConv.lhs;h=ecf7d52ae906b973539d912db306e76824f96eb3;hb=553e90d9a32ee1b1809430f260c401cc4169c6c7;hp=7389c0d62a3ffcb78e6c3f77e136f176f4e43376;hpb=89ea5818c80084440ea779bc93e6930a7a34752e;p=ghc-hetmet.git diff --git a/ghc/compiler/codeGen/CgRetConv.lhs b/ghc/compiler/codeGen/CgRetConv.lhs index 7389c0d..ecf7d52 100644 --- a/ghc/compiler/codeGen/CgRetConv.lhs +++ b/ghc/compiler/codeGen/CgRetConv.lhs @@ -1,5 +1,7 @@ % -% (c) The GRASP Project, Glasgow University, 1992-1995 +% (c) The GRASP Project, Glasgow University, 1992-1998 +% +% $Id: CgRetConv.lhs,v 1.34 2003/10/09 11:58:46 simonpj Exp $ % \section[CgRetConv]{Return conventions for the code generator} @@ -7,51 +9,29 @@ The datatypes and functions here encapsulate what there is to know about return conventions. \begin{code} -#include "HsVersions.h" - module CgRetConv ( - CtrlReturnConvention(..), DataReturnConvention(..), - + CtrlReturnConvention(..), ctrlReturnConvAlg, - dataReturnConvAlg, - dataReturnConvPrim, - - assignPrimOpResultRegs, - makePrimOpArgsRobust, - assignRegs + assignRegs, assignAllRegs ) where -IMP_Ubiq(){-uitous-} -IMPORT_DELOOPER(AbsCLoop) -- paranoia checking +#include "HsVersions.h" import AbsCSyn -- quite a few things -import AbsCUtils ( mkAbstractCs, getAmodeRep, - amodeCanSurviveGC - ) import Constants ( mAX_FAMILY_SIZE_FOR_VEC_RETURNS, mAX_Vanilla_REG, mAX_Float_REG, - mAX_Double_REG - ) -import CmdLineOpts ( opt_ReturnInRegsThreshold ) -import Id ( isDataCon, dataConRawArgTys, - SYN_IE(DataCon), GenId{-instance Eq-}, - SYN_IE(Id) - ) -import Maybes ( catMaybes ) -import Outputable ( PprStyle(..), Outputable(..) ) -import PprType ( TyCon{-instance Outputable-} ) -import PrimOp ( primOpCanTriggerGC, - getPrimOpResultInfo, PrimOpResultInfo(..), - PrimOp{-instance Outputable-} - ) -import PrimRep ( isFloatingRep, PrimRep(..) ) -import TyCon ( tyConDataCons, tyConFamilySize ) -import Type ( typePrimRep ) -import Pretty ( Doc ) -import Util ( zipWithEqual, mapAccumL, isn'tIn, - pprError, pprTrace, panic, assertPanic, assertPprPanic + mAX_Double_REG, mAX_Long_REG, + mAX_Real_Vanilla_REG, mAX_Real_Float_REG, + mAX_Real_Double_REG, mAX_Real_Long_REG ) +import CmdLineOpts ( opt_Unregisterised ) +import Maybes ( mapCatMaybes ) +import PrimRep ( isFloatingRep, PrimRep(..), is64BitRep ) +import TyCon ( TyCon, tyConFamilySize ) +import Util ( isn'tIn ) +import FastTypes +import Outputable \end{code} %************************************************************************ @@ -67,22 +47,6 @@ data CtrlReturnConvention | UnvectoredReturn Int -- family size \end{code} -A @DataReturnConvention@ says how the data for a particular -data-constructor is returned. -\begin{code} -data DataReturnConvention - = ReturnInHeap - | ReturnInRegs [MagicId] -\end{code} -The register assignment given by a @ReturnInRegs@ obeys three rules: -\begin{itemize} -\item R1 is dead. -\item R2 points to the info table for the phantom constructor -\item The list of @MagicId@ is in the same order as the arguments - to the constructor. -\end{itemize} - - %************************************************************************ %* * \subsection[CgRetConv-algebraic]{Return conventions for algebraic datatypes} @@ -94,40 +58,16 @@ ctrlReturnConvAlg :: TyCon -> CtrlReturnConvention ctrlReturnConvAlg tycon = case (tyConFamilySize tycon) of - 0 -> pprTrace "ctrlReturnConvAlg:" (ppr PprDebug tycon) $ - UnvectoredReturn 0 -- e.g., w/ "data Bin" - size -> -- we're supposed to know... if (size > (1::Int) && size <= mAX_FAMILY_SIZE_FOR_VEC_RETURNS) then VectoredReturn size else - UnvectoredReturn size -\end{code} - -@dataReturnConvAlg@ determines the return conventions from the -(possibly specialised) data constructor. - -(See also @getDataConReturnConv@ (in @Id@).) We grab the types -of the data constructor's arguments. We feed them and a list of -available registers into @assign_reg@, which sequentially assigns -registers of the appropriate types to the arguments, based on the -types. If @assign_reg@ runs out of a particular kind of register, -then it gives up, returning @ReturnInHeap@. - -\begin{code} -dataReturnConvAlg :: DataCon -> DataReturnConvention - -dataReturnConvAlg data_con - = ASSERT2(isDataCon data_con, (ppr PprDebug data_con)) - case leftover_kinds of - [] -> ReturnInRegs reg_assignment - other -> ReturnInHeap -- Didn't fit in registers - where - arg_tys = dataConRawArgTys data_con - - (reg_assignment, leftover_kinds) - = assignRegs [node, infoptr] -- taken... - (map typePrimRep arg_tys) + UnvectoredReturn size + -- NB: unvectored returns Include size 0 (no constructors), so that + -- the following perverse code compiles (it crashed GHC in 5.02) + -- data T1 + -- data T2 = T2 !T1 Int + -- The only value of type T1 is bottom, which never returns anyway. \end{code} %************************************************************************ @@ -136,203 +76,167 @@ dataReturnConvAlg data_con %* * %************************************************************************ -WARNING! If you add a return convention which can return a pointer, -make sure you alter CgCase (cgPrimDefault) to generate the right sort -of heap check! \begin{code} dataReturnConvPrim :: PrimRep -> MagicId -dataReturnConvPrim IntRep = VanillaReg IntRep ILIT(1) -dataReturnConvPrim WordRep = VanillaReg WordRep ILIT(1) -dataReturnConvPrim AddrRep = VanillaReg AddrRep ILIT(1) -dataReturnConvPrim CharRep = VanillaReg CharRep ILIT(1) -dataReturnConvPrim FloatRep = FloatReg ILIT(1) -dataReturnConvPrim DoubleRep = DoubleReg ILIT(1) +dataReturnConvPrim PtrRep = VanillaReg PtrRep (_ILIT 1) +dataReturnConvPrim IntRep = VanillaReg IntRep (_ILIT 1) +dataReturnConvPrim WordRep = VanillaReg WordRep (_ILIT 1) +dataReturnConvPrim Int32Rep = VanillaReg Int32Rep (_ILIT 1) +dataReturnConvPrim Word32Rep = VanillaReg Word32Rep (_ILIT 1) +dataReturnConvPrim Int64Rep = LongReg Int64Rep (_ILIT 1) +dataReturnConvPrim Word64Rep = LongReg Word64Rep (_ILIT 1) +dataReturnConvPrim AddrRep = VanillaReg AddrRep (_ILIT 1) +dataReturnConvPrim CharRep = VanillaReg CharRep (_ILIT 1) +dataReturnConvPrim Int8Rep = VanillaReg Int8Rep (_ILIT 1) +dataReturnConvPrim FloatRep = FloatReg (_ILIT 1) +dataReturnConvPrim DoubleRep = DoubleReg (_ILIT 1) +dataReturnConvPrim StablePtrRep = VanillaReg StablePtrRep (_ILIT 1) dataReturnConvPrim VoidRep = VoidReg --- Return a primitive-array pointer in the usual register: -dataReturnConvPrim ArrayRep = VanillaReg ArrayRep ILIT(1) -dataReturnConvPrim ByteArrayRep = VanillaReg ByteArrayRep ILIT(1) - -dataReturnConvPrim StablePtrRep = VanillaReg StablePtrRep ILIT(1) -dataReturnConvPrim ForeignObjRep = VanillaReg ForeignObjRep ILIT(1) - #ifdef DEBUG -dataReturnConvPrim PtrRep = panic "dataReturnConvPrim: PtrRep" -dataReturnConvPrim _ = panic "dataReturnConvPrim: other" +dataReturnConvPrim rep = pprPanic "dataReturnConvPrim:" (ppr rep) #endif \end{code} -%******************************************************** -%* * -\subsection[primop-stuff]{Argument and return conventions for Prim Ops} -%* * -%******************************************************** - -\begin{code} -assignPrimOpResultRegs - :: PrimOp -- The constructors in canonical order - -> [MagicId] -- The return regs all concatenated to together, - -- (*including* one for the tag if necy) - -assignPrimOpResultRegs op - = case (getPrimOpResultInfo op) of - - ReturnsPrim kind -> [dataReturnConvPrim kind] - - ReturnsAlg tycon - -> let - cons = tyConDataCons tycon - result_regs = concat (map get_return_regs cons) - in - -- As R1 is dead, it can hold the tag if necessary - case cons of - [_] -> result_regs - other -> (VanillaReg IntRep ILIT(1)) : result_regs - where - get_return_regs con - = case (dataReturnConvAlg con) of - ReturnInRegs regs -> regs - ReturnInHeap -> panic "getPrimOpAlgResultRegs" -\end{code} - -@assignPrimOpArgsRobust@ is used only for primitive ops which may -trigger GC. [MAYBE (WDP 94/05)] For these, we pass all (nonRobust) -arguments in registers. This function assigns them and tells us which -of those registers are now live (because we've shoved a followable -argument into it). - -Bug: it is assumed that robust amodes cannot contain pointers. This -seems reasonable but isn't true. For example, \tr{Array#}'s -\tr{ForeignObj#}'s are pointers. (This is only known to bite on -\tr{_ccall_GC_} with a ForeignObj argument.) - -See after for some ADR comments... - -\begin{code} -makePrimOpArgsRobust - :: PrimOp - -> [CAddrMode] -- Arguments - -> ([CAddrMode], -- Arg registers - Int, -- Liveness mask - AbstractC) -- Simultaneous assignments to assign args to regs - -makePrimOpArgsRobust op arg_amodes - = ASSERT (primOpCanTriggerGC op) - let - non_robust_amodes = filter (not . amodeCanSurviveGC) arg_amodes - arg_kinds = map getAmodeRep non_robust_amodes - - (arg_regs, extra_args) - = assignRegs [{-nothing live-}] arg_kinds - - -- Check that all the args fit before returning arg_regs - final_arg_regs = case extra_args of - [] -> arg_regs - other -> pprError "Cannot allocate enough registers for primop (try rearranging code or reducing number of arguments?)" (ppr PprDebug op) - - arg_assts - = mkAbstractCs (zipWithEqual "assign_to_reg" assign_to_reg final_arg_regs non_robust_amodes) - - assign_to_reg reg_id amode = CAssign (CReg reg_id) amode - - safe_arg regs arg - | amodeCanSurviveGC arg = (regs, arg) - | otherwise = (tail regs, CReg (head regs)) - safe_amodes = snd (mapAccumL safe_arg final_arg_regs arg_amodes) - - liveness_mask = mkLiveRegsMask final_arg_regs - in - (safe_amodes, liveness_mask, arg_assts) -\end{code} - %************************************************************************ %* * \subsubsection[CgRetConv-regs]{Register assignment} %* * %************************************************************************ -How to assign registers. +How to assign registers for + + 1) Calling a fast entry point. + 2) Returning an unboxed tuple. + 3) Invoking an out-of-line PrimOp. + Registers are assigned in order. -If we run out, we don't attempt to assign -any further registers (even though we might have run out of only one kind of -register); we just return immediately with the left-overs specified. +If we run out, we don't attempt to assign any further registers (even +though we might have run out of only one kind of register); we just +return immediately with the left-overs specified. + +The alternative version @assignAllRegs@ uses the complete set of +registers, including those that aren't mapped to real machine +registers. This is used for calling special RTS functions and PrimOps +which expect their arguments to always be in the same registers. \begin{code} -assignRegs :: [MagicId] -- Unavailable registers - -> [PrimRep] -- Arg or result kinds to assign - -> ([MagicId], -- Register assignment in same order +assignRegs, assignAllRegs + :: [MagicId] -- Unavailable registers + -> [PrimRep] -- Arg or result kinds to assign + -> ([MagicId], -- Register assignment in same order -- for *initial segment of* input list - [PrimRep])-- leftover kinds + [PrimRep])-- leftover kinds assignRegs regs_in_use kinds = assign_reg kinds [] (mkRegTbl regs_in_use) - where - assign_reg :: [PrimRep] -- arg kinds being scrutinized - -> [MagicId] -- accum. regs assigned so far (reversed) - -> ([Int], [Int], [Int]) - -- regs still avail: Vanilla, Float, Double - -> ([MagicId], [PrimRep]) +assignAllRegs regs_in_use kinds + = assign_reg kinds [] (mkRegTbl_allRegs regs_in_use) - assign_reg (VoidRep:ks) acc supply - = assign_reg ks (VoidReg:acc) supply -- one VoidReg is enough for everybody! +assign_reg + :: [PrimRep] -- arg kinds being scrutinized + -> [MagicId] -- accum. regs assigned so far (reversed) + -> AvailRegs -- regs still avail: Vanilla, Float, Double, longs + -> ([MagicId], [PrimRep]) - assign_reg (FloatRep:ks) acc (vanilla_rs, IBOX(f):float_rs, double_rs) - = assign_reg ks (FloatReg f:acc) (vanilla_rs, float_rs, double_rs) +assign_reg (VoidRep:ks) acc supply + = assign_reg ks (VoidReg:acc) supply + -- one VoidReg is enough for everybody! - assign_reg (DoubleRep:ks) acc (vanilla_rs, float_rs, IBOX(d):double_rs) - = assign_reg ks (DoubleReg d:acc) (vanilla_rs, float_rs, double_rs) +assign_reg (FloatRep:ks) acc (vanilla_rs, f:float_rs, double_rs, long_rs) + = assign_reg ks (FloatReg (iUnbox f):acc) + (vanilla_rs, float_rs, double_rs, long_rs) - assign_reg (k:ks) acc (IBOX(v):vanilla_rs, float_rs, double_rs) - | not (isFloatingRep k) - = assign_reg ks (VanillaReg k v:acc) (vanilla_rs, float_rs, double_rs) +assign_reg (DoubleRep:ks) acc (vanilla_rs, float_rs, d:double_rs, long_rs) + = assign_reg ks (DoubleReg (iUnbox d):acc) + (vanilla_rs, float_rs, double_rs, long_rs) - -- The catch-all. It can happen because either - -- (a) we've assigned all the regs so leftover_ks is [] - -- (b) we couldn't find a spare register in the appropriate supply - -- or, I suppose, - -- (c) we came across a Kind we couldn't handle (this one shouldn't happen) - assign_reg leftover_ks acc _ = (reverse acc, leftover_ks) -\end{code} +assign_reg (Word64Rep:ks) acc (vanilla_rs, float_rs, double_rs, u:long_rs) + = assign_reg ks (LongReg Word64Rep (iUnbox u):acc) + (vanilla_rs, float_rs, double_rs, long_rs) -Register supplies. Vanilla registers can contain pointers, Ints, Chars. +assign_reg (Int64Rep:ks) acc (vanilla_rs, float_rs, double_rs, l:long_rs) + = assign_reg ks (LongReg Int64Rep (iUnbox l):acc) + (vanilla_rs, float_rs, double_rs, long_rs) + +assign_reg (k:ks) acc (v:vanilla_rs, float_rs, double_rs, long_rs) + | not (isFloatingRep k || is64BitRep k) + = assign_reg ks (VanillaReg k (iUnbox v):acc) + (vanilla_rs, float_rs, double_rs, long_rs) + +-- The catch-all. It can happen because either +-- (a) we've assigned all the regs so leftover_ks is [] +-- (b) we couldn't find a spare register in the appropriate supply +-- or, I suppose, +-- (c) we came across a Kind we couldn't handle (this one shouldn't happen) +assign_reg leftover_ks acc _ = (reverse acc, leftover_ks) -\begin{code} -vanillaRegNos :: [Int] -vanillaRegNos = [1 .. mAX_Vanilla_REG] \end{code} +Register supplies. Vanilla registers can contain pointers, Ints, Chars. Floats and doubles have separate register supplies. +We take these register supplies from the *real* registers, i.e. those +that are guaranteed to map to machine registers. + \begin{code} -floatRegNos, doubleRegNos :: [Int] -floatRegNos = [1 .. mAX_Float_REG] -doubleRegNos = [1 .. mAX_Double_REG] +useVanillaRegs | opt_Unregisterised = 0 + | otherwise = mAX_Real_Vanilla_REG +useFloatRegs | opt_Unregisterised = 0 + | otherwise = mAX_Real_Float_REG +useDoubleRegs | opt_Unregisterised = 0 + | otherwise = mAX_Real_Double_REG +useLongRegs | opt_Unregisterised = 0 + | otherwise = mAX_Real_Long_REG + +vanillaRegNos, floatRegNos, doubleRegNos, longRegNos :: [Int] +vanillaRegNos = regList useVanillaRegs +floatRegNos = regList useFloatRegs +doubleRegNos = regList useDoubleRegs +longRegNos = regList useLongRegs + +allVanillaRegNos, allFloatRegNos, allDoubleRegNos, allLongRegNos :: [Int] +allVanillaRegNos = regList mAX_Vanilla_REG +allFloatRegNos = regList mAX_Float_REG +allDoubleRegNos = regList mAX_Double_REG +allLongRegNos = regList mAX_Long_REG + +regList 0 = [] +regList n = [1 .. n] + +type AvailRegs = ( [Int] -- available vanilla regs. + , [Int] -- floats + , [Int] -- doubles + , [Int] -- longs (int64 and word64) + ) + +mkRegTbl :: [MagicId] -> AvailRegs +mkRegTbl regs_in_use + = mkRegTbl' regs_in_use vanillaRegNos floatRegNos doubleRegNos longRegNos -mkRegTbl :: [MagicId] -> ([Int], [Int], [Int]) +mkRegTbl_allRegs :: [MagicId] -> AvailRegs +mkRegTbl_allRegs regs_in_use + = mkRegTbl' regs_in_use allVanillaRegNos allFloatRegNos allDoubleRegNos allLongRegNos -mkRegTbl regs_in_use - = (ok_vanilla, ok_float, ok_double) +mkRegTbl' regs_in_use vanillas floats doubles longs + = (ok_vanilla, ok_float, ok_double, ok_long) where - ok_vanilla = catMaybes (map (select (VanillaReg VoidRep)) (taker vanillaRegNos)) - ok_float = catMaybes (map (select FloatReg) floatRegNos) - ok_double = catMaybes (map (select DoubleReg) doubleRegNos) - - taker :: [Int] -> [Int] - taker rs - = case (opt_ReturnInRegsThreshold) of - Nothing -> rs -- no flag set; use all of them - Just n -> take n rs + ok_vanilla = mapCatMaybes (select (VanillaReg VoidRep)) vanillas + ok_float = mapCatMaybes (select FloatReg) floats + ok_double = mapCatMaybes (select DoubleReg) doubles + ok_long = mapCatMaybes (select (LongReg Int64Rep)) longs + -- rep isn't looked at, hence we can use any old rep. - select :: (FAST_INT -> MagicId) -> Int{-cand-} -> Maybe Int + select :: (FastInt -> MagicId) -> Int{-cand-} -> Maybe Int -- one we've unboxed the Int, we make a MagicId -- and see if it is already in use; if not, return its number. - select mk_reg_fun cand@IBOX(i) + select mk_reg_fun cand = let - reg = mk_reg_fun i + reg = mk_reg_fun (iUnbox cand) in if reg `not_elem` regs_in_use then Just cand