X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FcodeGen%2FCgCon.lhs;h=3cd67e42942c0ff69da1d624ddac27147642ef33;hb=423d477bfecd490de1449c59325c8776f91d7aac;hp=1d71cd03f4232b0c2af8337dda311d3de4ee51ef;hpb=7e602b0a11e567fcb035d1afd34015aebcf9a577;p=ghc-hetmet.git diff --git a/ghc/compiler/codeGen/CgCon.lhs b/ghc/compiler/codeGen/CgCon.lhs index 1d71cd0..3cd67e4 100644 --- a/ghc/compiler/codeGen/CgCon.lhs +++ b/ghc/compiler/codeGen/CgCon.lhs @@ -11,48 +11,53 @@ with {\em constructors} on the RHSs of let(rec)s. See also module CgCon ( cgTopRhsCon, buildDynCon, bindConArgs, bindUnboxedTupleComponents, - cgReturnDataCon + cgReturnDataCon, + cgTyCon ) where #include "HsVersions.h" import CgMonad -import AbsCSyn import StgSyn -import AbsCUtils ( getAmodeRep ) import CgBindery ( getArgAmodes, bindNewToNode, - bindArgsToRegs, newTempAmodeAndIdInfo, - idInfoToAmode, stableAmodeIdInfo, - heapIdInfo, CgIdInfo, bindNewToStack - ) -import CgStackery ( mkTaggedVirtStkOffsets, freeStackSlots ) -import CgUsages ( getRealSp, getVirtSp, setRealAndVirtualSp ) -import CgClosure ( cgTopRhsClosure ) -import CgRetConv ( assignRegs ) -import Constants ( mAX_INTLIKE, mIN_INTLIKE ) -import CgHeapery ( allocDynClosure ) -import CgTailCall ( performReturn, mkStaticAlgReturnCode, doTailCall, - mkUnboxedTupleReturnCode ) -import CLabel ( mkClosureLabel, mkStaticClosureLabel ) -import ClosureInfo ( mkClosureLFInfo, mkConLFInfo, mkLFArgument, - layOutDynCon, layOutDynClosure, - layOutStaticClosure + bindArgsToRegs, idInfoToAmode, stableIdInfo, + heapIdInfo, CgIdInfo, bindArgsToStack ) +import CgStackery ( mkVirtStkOffsets, freeStackSlots, + getRealSp, getVirtSp, setRealAndVirtualSp ) +import CgUtils ( addIdReps, cmmLabelOffW, emitRODataLits, emitDataLits ) +import CgCallConv ( assignReturnRegs ) +import Constants ( mAX_INTLIKE, mIN_INTLIKE, mAX_CHARLIKE, mIN_CHARLIKE ) +import CgHeapery ( allocDynClosure, layOutDynConstr, + layOutStaticConstr, mkStaticClosureFields ) +import CgTailCall ( performReturn, emitKnownConReturnCode, returnUnboxedTuple ) +import CgProf ( mkCCostCentreStack, ldvEnter, curCCS ) +import CgTicky +import CgInfoTbls ( emitClosureCodeAndInfoTable, dataConTagZ ) +import CLabel ( mkClosureLabel, mkRtsDataLabel, mkClosureTblLabel ) +import ClosureInfo ( mkConLFInfo, mkLFArgument ) +import CmmUtils ( mkLblExpr ) +import Cmm +import SMRep ( WordOff, CgRep, separateByPtrFollowness, + fixedHdrSize, typeCgRep ) import CostCentre ( currentOrSubsumedCCS, dontCareCCS, CostCentreStack, currentCCS ) -import DataCon ( DataCon, dataConName, dataConTag, dataConTyCon, - isUnboxedTupleCon ) -import MkId ( mkDataConId ) -import Id ( Id, idName, idType, idPrimRep ) -import Const ( Con(..), Literal(..) ) +import Constants ( mIN_INTLIKE, mAX_INTLIKE, mIN_CHARLIKE, mAX_CHARLIKE ) +import TyCon ( TyCon, tyConDataCons, isEnumerationTyCon, tyConName ) +import DataCon ( DataCon, dataConRepArgTys, isNullaryDataCon, + isUnboxedTupleCon, dataConWorkId, + dataConName, dataConRepArity + ) +import Id ( Id, idName, isDeadBinder ) +import Type ( Type ) import PrelInfo ( maybeCharLikeCon, maybeIntLikeCon ) -import PrimRep ( PrimRep(..) ) -import BasicTypes ( TopLevelFlag(..) ) -import Util -import Panic ( assertPanic ) +import Outputable +import Util ( lengthIs ) +import ListSetOps ( assocMaybe ) \end{code} + %************************************************************************ %* * \subsection[toplevel-constructors]{Top-level constructors} @@ -63,95 +68,36 @@ import Panic ( assertPanic ) cgTopRhsCon :: Id -- Name of thing bound to this RHS -> DataCon -- Id -> [StgArg] -- Args - -> Bool -- All zero-size args (see buildDynCon) -> FCode (Id, CgIdInfo) -\end{code} - -Special Case: Constructors some of whose arguments are of \tr{Double#} -type, {\em or} which are ``lit lits'' (which are given \tr{Addr#} -type). - -These ones have to be compiled as re-entrant thunks rather than -closures, because we can't figure out a way to persuade C to allow us -to initialise a static closure with Doubles! Thus, for \tr{x = 2.0} -(defaults to Double), we get: - -\begin{verbatim} --- The STG syntax: - Main.x = MkDouble [2.0##] - --- C Code: - --- closure: - SET_STATIC_HDR(Main_x_closure,Main_x_static,CC_DATA,,EXTDATA_RO) - }; --- its *own* info table: - STATIC_INFO_TABLE(Main_x,Main_x_entry,,,,EXTFUN,???,":MkDouble","Double"); --- with its *own* entry code: - STGFUN(Main_x_entry) { - P_ u1701; - RetDouble1=2.0; - u1701=(P_)*SpB; - SpB=SpB-1; - JMP_(u1701[0]); - } -\end{verbatim} - -The above has the down side that each floating-point constant will end -up with its own info table (rather than sharing the MkFloat/MkDouble -ones). On the plus side, however, it does return a value (\tr{2.0}) -{\em straight away}. - -Here, then is the implementation: just pretend it's a non-updatable -thunk. That is, instead of - - x = D# 3.455# - -pretend we've seen - - x = [] \n [] -> D# 3.455# - -\begin{code} -top_ccc = mkCCostCentreStack dontCareCCS -- because it's static data - -cgTopRhsCon bndr con args all_zero_size_args - | any isLitLitArg args - = cgTopRhsClosure bndr dontCareCCS NoStgBinderInfo NoSRT [] body lf_info - where - body = StgCon (DataCon con) args rhs_ty - lf_info = mkClosureLFInfo bndr TopLevel [] ReEntrant [] - rhs_ty = idType bndr -\end{code} - -OK, so now we have the general case. - -\begin{code} -cgTopRhsCon id con args all_zero_size_args - = ( - -- LAY IT OUT - getArgAmodes args `thenFC` \ amodes -> - - let - (closure_info, amodes_w_offsets) - = layOutStaticClosure name getAmodeRep amodes lf_info - in - - -- BUILD THE OBJECT - absC (CStaticClosure - closure_label -- Labelled with the name on lhs of defn - closure_info -- Closure is static - top_ccc - (map fst amodes_w_offsets)) -- Sorted into ptrs first, then nonptrs - - ) `thenC` - - -- RETURN - returnFC (id, stableAmodeIdInfo id (CLbl closure_label PtrRep) lf_info) - where - con_tycon = dataConTyCon con - lf_info = mkConLFInfo con - closure_label = mkClosureLabel name - name = idName id +cgTopRhsCon id con args + = ASSERT( not (isDllConApp con args) ) + ASSERT( args `lengthIs` dataConRepArity con ) + do { -- LAY IT OUT + ; amodes <- getArgAmodes args + + ; let + name = idName id + lf_info = mkConLFInfo con + closure_label = mkClosureLabel name + caffy = any stgArgHasCafRefs args + (closure_info, amodes_w_offsets) = layOutStaticConstr con amodes + closure_rep = mkStaticClosureFields + closure_info + dontCareCCS -- Because it's static data + caffy -- Has CAF refs + payload + + payload = map get_lit amodes_w_offsets + get_lit (CmmLit lit, _offset) = lit + get_lit other = pprPanic "CgCon.get_lit" (ppr other) + -- NB1: amodes_w_offsets is sorted into ptrs first, then non-ptrs + -- NB2: all the amodes should be Lits! + + -- BUILD THE OBJECT + ; emitDataLits closure_label closure_rep + + -- RETURN + ; returnFC (id, stableIdInfo id (mkLblExpr closure_label) lf_info) } \end{code} %************************************************************************ @@ -162,19 +108,23 @@ cgTopRhsCon id con args all_zero_size_args \subsection[code-for-constructors]{The code for constructors} \begin{code} -buildDynCon :: Id -- Name of the thing to which this constr will - -- be bound - -> CostCentreStack -- Where to grab cost centre from; - -- current CCS if currentOrSubsumedCCS - -> DataCon -- The data constructor - -> [CAddrMode] -- Its args - -> Bool -- True <=> all args (if any) are - -- of "zero size" (i.e., VoidRep); - -- The reason we don't just look at the - -- args is that we may be in a "knot", and - -- premature looking at the args will cause - -- the compiler to black-hole! - -> FCode CgIdInfo -- Return details about how to find it +buildDynCon :: Id -- Name of the thing to which this constr will + -- be bound + -> CostCentreStack -- Where to grab cost centre from; + -- current CCS if currentOrSubsumedCCS + -> DataCon -- The data constructor + -> [(CgRep,CmmExpr)] -- Its args + -> FCode CgIdInfo -- Return details about how to find it + +-- We used to pass a boolean indicating whether all the +-- args were of size zero, so we could use a static +-- construtor; but I concluded that it just isn't worth it. +-- Now I/O uses unboxed tuples there just aren't any constructors +-- with all size-zero args. +-- +-- The reason for having a separate argument, rather than looking at +-- the addr modes of the args is that we may be in a "knot", and +-- premature looking at the args will cause the compiler to black-hole! \end{code} First we deal with the case of zero-arity constructors. Now, they @@ -186,12 +136,18 @@ which have exclusively size-zero (VoidRep) args, we generate no code at all. \begin{code} -buildDynCon binder cc con args all_zero_size_args@True - = returnFC (stableAmodeIdInfo binder - (CLbl (mkStaticClosureLabel (dataConName con)) PtrRep) - (mkConLFInfo con)) +buildDynCon binder cc con [] + = returnFC (stableIdInfo binder + (mkLblExpr (mkClosureLabel (dataConName con))) + (mkConLFInfo con)) \end{code} +The following three paragraphs about @Char@-like and @Int@-like +closures are obsolete, but I don't understand the details well enough +to properly word them, sorry. I've changed the treatment of @Char@s to +be analogous to @Int@s: only a subset is preallocated, because @Char@ +has now 31 bits. Only literals are handled here. -- Qrczak + Now for @Char@-like closures. We generate an assignment of the address of the closure to a temporary. It would be possible simply to generate no code, and record the addressing mode in the environment, @@ -208,38 +164,42 @@ which is guaranteed in range. Because of this, we use can safely return an addressing mode. \begin{code} -buildDynCon binder cc con [arg_amode] all_zero_size_args@False - - | maybeCharLikeCon con - = absC (CAssign temp_amode (CCharLike arg_amode)) `thenC` - returnFC temp_id_info - - | maybeIntLikeCon con && in_range_int_lit arg_amode - = returnFC (stableAmodeIdInfo binder (CIntLike arg_amode) (mkConLFInfo con)) - where - (temp_amode, temp_id_info) = newTempAmodeAndIdInfo binder (mkConLFInfo con) - - in_range_int_lit (CLit (MachInt val _)) = val <= mAX_INTLIKE && val >= mIN_INTLIKE - in_range_int_lit other_amode = False - - tycon = dataConTyCon con +buildDynCon binder cc con [arg_amode] + | maybeIntLikeCon con + , (_, CmmLit (CmmInt val _)) <- arg_amode + , let val_int = (fromIntegral val) :: Int + , val_int <= mAX_INTLIKE && val_int >= mIN_INTLIKE + = do { let intlike_lbl = mkRtsDataLabel SLIT("stg_INTLIKE_closure") + offsetW = (val_int - mIN_INTLIKE) * (fixedHdrSize + 1) + -- INTLIKE closures consist of a header and one word payload + intlike_amode = CmmLit (cmmLabelOffW intlike_lbl offsetW) + ; returnFC (stableIdInfo binder intlike_amode (mkConLFInfo con)) } + +buildDynCon binder cc con [arg_amode] + | maybeCharLikeCon con + , (_, CmmLit (CmmInt val _)) <- arg_amode + , let val_int = (fromIntegral val) :: Int + , val_int <= mAX_CHARLIKE && val_int >= mIN_CHARLIKE + = do { let charlike_lbl = mkRtsDataLabel SLIT("stg_CHARLIKE_closure") + offsetW = (val_int - mIN_CHARLIKE) * (fixedHdrSize + 1) + -- CHARLIKE closures consist of a header and one word payload + charlike_amode = CmmLit (cmmLabelOffW charlike_lbl offsetW) + ; returnFC (stableIdInfo binder charlike_amode (mkConLFInfo con)) } \end{code} Now the general case. \begin{code} -buildDynCon binder ccs con args all_zero_size_args@False - = allocDynClosure closure_info use_cc blame_cc amodes_w_offsets `thenFC` \ hp_off -> - returnFC (heapIdInfo binder hp_off lf_info) +buildDynCon binder ccs con args + = do { hp_off <- allocDynClosure closure_info use_cc blame_cc amodes_w_offsets + ; returnFC (heapIdInfo binder hp_off lf_info) } where - (closure_info, amodes_w_offsets) - = layOutDynClosure (idName binder) getAmodeRep args lf_info lf_info = mkConLFInfo con + (closure_info, amodes_w_offsets) = layOutDynConstr con args use_cc -- cost-centre to stick in the object - = if currentOrSubsumedCCS ccs - then CReg CurCostCentre - else mkCCostCentreStack ccs + | currentOrSubsumedCCS ccs = curCCS + | otherwise = CmmLit (mkCCostCentreStack ccs) blame_cc = use_cc -- cost-centre on which to blame the alloc (same) \end{code} @@ -258,16 +218,13 @@ binders $args$, assuming that we have just returned from a @case@ which found a $con$. \begin{code} -bindConArgs - :: DataCon -> [Id] -- Constructor and args - -> Code - +bindConArgs :: DataCon -> [Id] -> Code bindConArgs con args = ASSERT(not (isUnboxedTupleCon con)) mapCs bind_arg args_w_offsets where - bind_arg (arg, offset) = bindNewToNode arg offset mkLFArgument - (_, args_w_offsets) = layOutDynCon con idPrimRep args + bind_arg (arg, offset) = bindNewToNode arg offset (mkLFArgument arg) + (_, args_w_offsets) = layOutDynConstr con (addIdReps args) \end{code} Unboxed tuples are handled slightly differently - the object is @@ -275,38 +232,53 @@ returned in registers and on the stack instead of the heap. \begin{code} bindUnboxedTupleComponents - :: [Id] -- args - -> FCode ([MagicId], -- regs assigned - [(VirtualSpOffset,Int)], -- tag slots - Bool) -- any components on stack? + :: [Id] -- Args + -> FCode ([(Id,GlobalReg)], -- Regs assigned + WordOff, -- Number of pointer stack slots + WordOff, -- Number of non-pointer stack slots + VirtualSpOffset) -- Offset of return address slot + -- (= realSP on entry) bindUnboxedTupleComponents args - = -- Assign as many components as possible to registers - let (arg_regs, leftovers) = assignRegs [] (map idPrimRep args) - (reg_args, stk_args) = splitAt (length arg_regs) args - in - - -- Allocate the rest on the stack (ToDo: separate out pointers) - getVirtSp `thenFC` \ vsp -> - getRealSp `thenFC` \ rsp -> - let (top_sp, stk_offsets, tags) = - mkTaggedVirtStkOffsets rsp idPrimRep stk_args - in - - -- The stack pointer points to the last stack-allocated component - setRealAndVirtualSp top_sp `thenC` - - -- need to explicitly free any empty slots we just jumped over - (if vsp < rsp then freeStackSlots [vsp+1 .. rsp] else nopC) `thenC` - - bindArgsToRegs reg_args arg_regs `thenC` - mapCs bindNewToStack stk_offsets `thenC` - returnFC (arg_regs,tags, not (null stk_offsets)) + = do { + vsp <- getVirtSp + ; rsp <- getRealSp + + -- Assign as many components as possible to registers + ; let (reg_args, stk_args) = assignReturnRegs (addIdReps args) + + -- Separate the rest of the args into pointers and non-pointers + (ptr_args, nptr_args) = separateByPtrFollowness stk_args + + -- Allocate the rest on the stack + -- The real SP points to the return address, above which any + -- leftover unboxed-tuple components will be allocated + (ptr_sp, ptr_offsets) = mkVirtStkOffsets rsp ptr_args + (nptr_sp, nptr_offsets) = mkVirtStkOffsets ptr_sp nptr_args + ptrs = ptr_sp - rsp + nptrs = nptr_sp - ptr_sp + + -- The stack pointer points to the last stack-allocated component + ; setRealAndVirtualSp nptr_sp + + -- We have just allocated slots starting at real SP + 1, and set the new + -- virtual SP to the topmost allocated slot. + -- If the virtual SP started *below* the real SP, we've just jumped over + -- some slots that won't be in the free-list, so put them there + -- This commonly happens because we've freed the return-address slot + -- (trimming back the virtual SP), but the real SP still points to that slot + ; freeStackSlots [vsp+1,vsp+2 .. rsp] + + ; bindArgsToRegs reg_args + ; bindArgsToStack ptr_offsets + ; bindArgsToStack nptr_offsets + + ; returnFC (reg_args, ptrs, nptrs, rsp) } \end{code} %************************************************************************ %* * -\subsubsection[CgRetConv-cgReturnDataCon]{Actually generate code for a constructor return} + Actually generate code for a constructor return %* * %************************************************************************ @@ -314,85 +286,150 @@ bindUnboxedTupleComponents args Note: it's the responsibility of the @cgReturnDataCon@ caller to be sure the @amodes@ passed don't conflict with each other. \begin{code} -cgReturnDataCon :: DataCon -> [CAddrMode] -> Bool -> Code - -cgReturnDataCon con amodes all_zero_size_args - = getEndOfBlockInfo `thenFC` \ (EndOfBlockInfo args_sp sequel) -> - - case sequel of - - CaseAlts _ (Just (alts, Just (maybe_deflt_binder, (_,deflt_lbl)))) - | not (dataConTag con `is_elem` map fst alts) - -> - -- Special case! We're returning a constructor to the default case - -- of an enclosing case. For example: - -- - -- case (case e of (a,b) -> C a b) of - -- D x -> ... - -- y -> ...... - -- - -- In this case, - -- if the default is a non-bind-default (ie does not use y), - -- then we should simply jump to the default join point; - -- - -- if the default is a bind-default (ie does use y), we - -- should return the constructor in the heap, - -- pointed to by Node. - - case maybe_deflt_binder of - Just binder -> - ASSERT(not (isUnboxedTupleCon con)) - buildDynCon binder currentCCS con amodes all_zero_size_args - `thenFC` \ idinfo -> - idInfoToAmode PtrRep idinfo `thenFC` \ amode -> - performReturn (move_to_reg amode node) jump_to_join_point - - Nothing -> - performReturn AbsCNop {- No reg assts -} jump_to_join_point - where - is_elem = isIn "cgReturnDataCon" - jump_to_join_point sequel = absC (CJump (CLbl deflt_lbl CodePtrRep)) - -- Ignore the sequel: we've already looked at it above - - other_sequel -- The usual case - - | isUnboxedTupleCon con -> - -- Return unboxed tuple in registers - let (ret_regs, leftovers) = - assignRegs [] (map getAmodeRep amodes) - in - doTailCall amodes ret_regs - mkUnboxedTupleReturnCode - (length leftovers) {- fast args arity -} - AbsCNop {-no pending assigments-} - Nothing {-not a let-no-escape-} - False {-node doesn't point-} - - | otherwise -> - -- BUILD THE OBJECT IN THE HEAP - -- The first "con" says that the name bound to this - -- closure is "con", which is a bit of a fudge, but it only - -- affects profiling - - -- This Id is also used to get a unique for a - -- temporary variable, if the closure is a CHARLIKE. - -- funilly enough, this makes the unique always come - -- out as '54' :-) - buildDynCon (mkDataConId con) currentCCS - con amodes all_zero_size_args - `thenFC` \ idinfo -> - idInfoToAmode PtrRep idinfo `thenFC` \ amode -> - - - -- RETURN - profCtrC SLIT("TICK_RET_CON") [mkIntCLit (length amodes)] `thenC` - -- could use doTailCall here. - performReturn (move_to_reg amode node) - (mkStaticAlgReturnCode con) - +cgReturnDataCon :: DataCon -> [(CgRep, CmmExpr)] -> Code + +cgReturnDataCon con amodes + = ASSERT( amodes `lengthIs` dataConRepArity con ) + do { EndOfBlockInfo _ sequel <- getEndOfBlockInfo + ; case sequel of + CaseAlts _ (Just (alts, deflt_lbl)) bndr _ + -> -- Ho! We know the constructor so we can + -- go straight to the right alternative + case assocMaybe alts (dataConTagZ con) of { + Just join_lbl -> build_it_then (jump_to join_lbl) ; + Nothing + -- Special case! We're returning a constructor to the default case + -- of an enclosing case. For example: + -- + -- case (case e of (a,b) -> C a b) of + -- D x -> ... + -- y -> ...... + -- + -- In this case, + -- if the default is a non-bind-default (ie does not use y), + -- then we should simply jump to the default join point; + + | isDeadBinder bndr -> performReturn (jump_to deflt_lbl) + | otherwise -> build_it_then (jump_to deflt_lbl) } + + other_sequel -- The usual case + | isUnboxedTupleCon con -> returnUnboxedTuple amodes + | otherwise -> build_it_then (emitKnownConReturnCode con) + } where - con_name = dataConName con + jump_to lbl = stmtC (CmmJump (CmmLit (CmmLabel lbl)) []) + build_it_then return_code + = do { -- BUILD THE OBJECT IN THE HEAP + -- The first "con" says that the name bound to this + -- closure is "con", which is a bit of a fudge, but it only + -- affects profiling + + -- This Id is also used to get a unique for a + -- temporary variable, if the closure is a CHARLIKE. + -- funnily enough, this makes the unique always come + -- out as '54' :-) + tickyReturnNewCon (length amodes) + ; idinfo <- buildDynCon (dataConWorkId con) currentCCS con amodes + ; amode <- idInfoToAmode idinfo + ; checkedAbsC (CmmAssign nodeReg amode) + ; performReturn return_code } +\end{code} + + +%************************************************************************ +%* * + Generating static stuff for algebraic data types +%* * +%************************************************************************ + + [These comments are rather out of date] + +\begin{tabular}{lll} +Info tbls & Macro & Kind of constructor \\ +\hline +info & @CONST_INFO_TABLE@& Zero arity (no info -- compiler uses static closure)\\ +info & @CHARLIKE_INFO_TABLE@& Charlike (no info -- compiler indexes fixed array)\\ +info & @INTLIKE_INFO_TABLE@& Intlike; the one macro generates both info tbls\\ +info & @SPEC_INFO_TABLE@& SPECish, and bigger than or equal to @MIN_UPD_SIZE@\\ +info & @GEN_INFO_TABLE@& GENish (hence bigger than or equal to @MIN_UPD_SIZE@)\\ +\end{tabular} + +Possible info tables for constructor con: + +\begin{description} +\item[@_con_info@:] +Used for dynamically let(rec)-bound occurrences of +the constructor, and for updates. For constructors +which are int-like, char-like or nullary, when GC occurs, +the closure tries to get rid of itself. - move_to_reg :: CAddrMode -> MagicId -> AbstractC - move_to_reg src_amode dest_reg = CAssign (CReg dest_reg) src_amode +\item[@_static_info@:] +Static occurrences of the constructor +macro: @STATIC_INFO_TABLE@. +\end{description} + +For zero-arity constructors, \tr{con}, we NO LONGER generate a static closure; +it's place is taken by the top level defn of the constructor. + +For charlike and intlike closures there is a fixed array of static +closures predeclared. + +\begin{code} +cgTyCon :: TyCon -> FCode [Cmm] -- each constructor gets a separate Cmm +cgTyCon tycon + = do { constrs <- mapM (getCmm . cgDataCon) (tyConDataCons tycon) + + -- Generate a table of static closures for an enumeration type + -- Put the table after the data constructor decls, because the + -- datatype closure table (for enumeration types) + -- to (say) PrelBase_$wTrue_closure, which is defined in code_stuff + ; extra <- + if isEnumerationTyCon tycon then do + tbl <- getCmm (emitRODataLits (mkClosureTblLabel + (tyConName tycon)) + [ CmmLabel (mkClosureLabel (dataConName con)) + | con <- tyConDataCons tycon]) + return [tbl] + else + return [] + + ; return (extra ++ constrs) + } +\end{code} + +Generate the entry code, info tables, and (for niladic constructor) the +static closure, for a constructor. + +\begin{code} +cgDataCon :: DataCon -> Code +cgDataCon data_con + = do { -- Don't need any dynamic closure code for zero-arity constructors + whenC (not (isNullaryDataCon data_con)) + (emit_info dyn_cl_info tickyEnterDynCon) + + -- Dynamic-Closure first, to reduce forward references + ; emit_info static_cl_info tickyEnterStaticCon } + + where + emit_info cl_info ticky_code + = do { code_blks <- getCgStmts the_code + ; emitClosureCodeAndInfoTable cl_info [] code_blks } + where + the_code = do { ticky_code + ; ldvEnter (CmmReg nodeReg) + ; body_code } + + arg_reps :: [(CgRep, Type)] + arg_reps = [(typeCgRep ty, ty) | ty <- dataConRepArgTys data_con] + + -- To allow the debuggers, interpreters, etc to cope with static + -- data structures (ie those built at compile time), we take care that + -- info-table contains the information we need. + (static_cl_info, _) = layOutStaticConstr data_con arg_reps + (dyn_cl_info, arg_things) = layOutDynConstr data_con arg_reps + + body_code = do { -- NB: We don't set CC when entering data (WDP 94/06) + tickyReturnOldCon (length arg_things) + ; performReturn (emitKnownConReturnCode data_con) } + -- noStmts: Ptr to thing already in Node \end{code}