%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[CgConTbls]{Info tables and update bits for constructors}
import AbsCSyn
import CgMonad
-import AbsCUtils ( mkAbsCStmts, mkAbstractCs, magicIdPrimRep )
-import Constants ( uF_UPDATEE )
-import CgHeapery ( heapCheck, allocDynClosure )
-import CgRetConv ( dataReturnConvAlg, ctrlReturnConvAlg,
- CtrlReturnConvention(..),
- DataReturnConvention(..)
- )
+import StgSyn ( SRT(..) )
+import AbsCUtils ( mkAbstractCs )
import CgTailCall ( performReturn, mkStaticAlgReturnCode )
-import CgUsages ( getHpRelOffset )
-import CLabel ( mkConEntryLabel, mkStaticClosureLabel,
- mkConUpdCodePtrVecLabel,
- mkStdUpdCodePtrVecLabel, mkStdUpdVecTblLabel
- )
+import CLabel ( mkConEntryLabel, mkStaticClosureLabel )
import ClosureInfo ( layOutStaticClosure, layOutDynCon,
- layOutPhantomClosure, closurePtrsSize,
- fitsMinUpdSize, mkConLFInfo,
- infoTableLabelFromCI, dataConLiveness,
- ClosureInfo
+ mkConLFInfo, ClosureInfo
)
-import CostCentre ( dontCareCostCentre, CostCentre )
+import CostCentre ( dontCareCCS )
import FiniteMap ( fmToList, FiniteMap )
-import HeapOffs ( zeroOff, VirtualHeapOffset )
-import Id ( dataConTag, dataConRawArgTys,
- dataConNumFields, fIRST_TAG,
- emptyIdSet,
- GenId{-instance NamedThing-}, Id
- )
+import DataCon ( DataCon, dataConTag, dataConName, dataConRawArgTys )
+import Const ( Con(..) )
import Name ( getOccString )
import PrimRep ( getPrimRepSize, PrimRep(..) )
-import TyCon ( tyConDataCons, mkSpecTyCon, TyCon )
+import TyCon ( tyConDataCons, TyCon )
import Type ( typePrimRep, Type )
-import Util ( panic )
-
-mkSameSpecCon = panic "CgConTbls.mkSameSpecCon (ToDo)"
+import BasicTypes ( TopLevelFlag(..) )
+import Outputable
\end{code}
For every constructor we generate the following info tables:
A static info table, for static instances of the constructor,
- For constructors which return in registers (and only them),
- an "inregs" info table. This info table is rather emaciated;
- it only contains update code and tag.
-
Plus:
\begin{tabular}{lll}
Possible info tables for constructor con:
\begin{description}
-\item[@con_info@:]
+\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.
-\item[@con_inregs_info@:]
-Used when returning a new constructor in registers.
-Only for return-in-regs constructors.
-Macro: @INREGS_INFO_TABLE@.
-
-\item[@con_static_info@:]
+\item[@_static_info@:]
Static occurrences of the constructor
macro: @STATIC_INFO_TABLE@.
\end{description}
For zero-arity constructors, \tr{con}, we also generate a static closure:
\begin{description}
-\item[@con_closure@:]
+\item[@_closure@:]
A single static copy of the (zero-arity) constructor itself.
\end{description}
-> AbstractC -- output
genStaticConBits comp_info gen_tycons tycon_specs
- = -- for each type constructor:
+ = ASSERT( null (fmToList tycon_specs) )
+ -- We don't do specialised type constructors any more
+
+ -- for each type constructor:
-- grab all its data constructors;
-- for each one, generate an info table
-- for each specialised type constructor
-- since they may be duplicated in other modules
mkAbstractCs [ gen_for_tycon tc | tc <- gen_tycons ]
- `mkAbsCStmts`
- mkAbstractCs [ mkAbstractCs [ gen_for_spec_tycon tc spec
- | (imported_spec, spec) <- specs,
- -- no code generated if spec is imported
- not imported_spec
- ]
- | (tc, specs) <- fmToList tycon_specs ]
where
gen_for_tycon :: TyCon -> AbstractC
gen_for_tycon tycon
- = mkAbstractCs (map (genConInfo comp_info tycon) data_cons)
- `mkAbsCStmts`
- maybe_tycon_vtbl
- where
- data_cons = tyConDataCons tycon
- tycon_upd_label = mkStdUpdVecTblLabel tycon
-
- maybe_tycon_vtbl =
- case ctrlReturnConvAlg tycon of
- UnvectoredReturn 1 -> CRetUnVector tycon_upd_label
- (mk_upd_label tycon (head data_cons))
- UnvectoredReturn _ -> AbsCNop
- VectoredReturn _ -> CFlatRetVector tycon_upd_label
- (map (mk_upd_label tycon) data_cons)
- ------------------
- gen_for_spec_tycon :: TyCon -> [Maybe Type] -> AbstractC
-
- gen_for_spec_tycon tycon ty_maybes
- = mkAbstractCs (map (genConInfo comp_info spec_tycon) spec_data_cons)
- `mkAbsCStmts`
- maybe_spec_tycon_vtbl
- where
- data_cons = tyConDataCons tycon
-
- spec_tycon = mkSpecTyCon tycon ty_maybes
- spec_data_cons = map (mkSameSpecCon ty_maybes) data_cons
-
- spec_tycon_upd_label = mkStdUpdVecTblLabel spec_tycon
-
- maybe_spec_tycon_vtbl =
- case ctrlReturnConvAlg spec_tycon of
- UnvectoredReturn 1 -> CRetUnVector spec_tycon_upd_label
- (mk_upd_label spec_tycon (head spec_data_cons))
- UnvectoredReturn _ -> AbsCNop
- VectoredReturn _ -> CFlatRetVector spec_tycon_upd_label
- (map (mk_upd_label spec_tycon) spec_data_cons)
- ------------------
- mk_upd_label tycon con
- = CLbl
- (case (dataReturnConvAlg con) of
- ReturnInRegs _ -> mkConUpdCodePtrVecLabel tycon tag
- ReturnInHeap -> mkStdUpdCodePtrVecLabel tycon tag)
- CodePtrRep
- where
- tag = dataConTag con
+ = mkAbstractCs (map (genConInfo comp_info tycon) (tyConDataCons tycon))
\end{code}
%************************************************************************
static closure, for a constructor.
\begin{code}
-genConInfo :: CompilationInfo -> TyCon -> Id -> AbstractC
+genConInfo :: CompilationInfo -> TyCon -> DataCon -> AbstractC
genConInfo comp_info tycon data_con
= mkAbstractCs [
CSplitMarker,
- inregs_upd_maybe,
closure_code,
static_code,
closure_maybe]
-- 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_ci,_) = layOutStaticClosure data_con typePrimRep arg_tys (mkConLFInfo data_con)
+ (static_ci,_) = layOutStaticClosure con_name typePrimRep arg_tys
+ (mkConLFInfo data_con)
body = (initC comp_info (
- profCtrC SLIT("ENT_CON") [CReg node] `thenC`
+ profCtrC SLIT("TICK_ENT_CON") [CReg node] `thenC`
body_code))
entry_addr = CLbl entry_label CodePtrRep
con_descr = getOccString data_con
- closure_code = CClosureInfoAndCode closure_info body Nothing
- stdUpd con_descr
- (dataConLiveness closure_info)
- static_code = CClosureInfoAndCode static_ci body Nothing
- stdUpd con_descr
- (dataConLiveness static_ci)
+ -- Don't need any dynamic closure code for zero-arity constructors
+ closure_code = if zero_arity_con then
+ AbsCNop
+ else
+ CClosureInfoAndCode closure_info body Nothing
+ srt_info con_descr
- inregs_upd_maybe = genPhantomUpdInfo comp_info tycon data_con
+ srt_info = (error "genConInfo: no srt label", NoSRT)
- stdUpd = CLbl (mkStdUpdCodePtrVecLabel tycon tag) CodePtrRep
+ static_code = CClosureInfoAndCode static_ci body Nothing
+ srt_info con_descr
- tag = dataConTag data_con
+ tag = dataConTag data_con
- cost_centre = mkCCostCentre dontCareCostCentre -- not worried about static data costs
+ cost_centre = mkCCostCentreStack dontCareCCS -- not worried about static data costs
-- For zero-arity data constructors, or, more accurately,
-- those which only have VoidRep args (or none):
-- We make the closure too (not just info tbl), so that we can share
-- one copy throughout.
- closure_maybe = if not (all zero_size arg_tys) then
+ closure_maybe = if not zero_arity_con then
AbsCNop
else
CStaticClosure closure_label -- Label for closure
static_ci -- Info table
cost_centre
- [{-No args! A slight lie for constrs with VoidRep args-}]
+ [{-No args! A slight lie for constrs
+ with VoidRep args-}]
zero_size arg_ty = getPrimRepSize (typePrimRep arg_ty) == 0
+ zero_arity_con = all zero_size arg_tys
+
arg_tys = dataConRawArgTys data_con
- entry_label = mkConEntryLabel data_con
- closure_label = mkStaticClosureLabel data_con
+ entry_label = mkConEntryLabel con_name
+ closure_label = mkStaticClosureLabel con_name
+ con_name = dataConName data_con
\end{code}
-The entry code for a constructor now loads the info ptr by indirecting
-node. The alternative is to load the info ptr in the enter-via-node
-sequence. There's is a trade-off here:
-
- * If the architecture can perform an indirect jump through a
- register in one instruction, or if the info ptr is not a
- real register, then *not* loading the info ptr on an enter
- is a win.
-
- * If the enter-via-node code is identical whether we load the
- info ptr or not, then doing it is a win (it means we don't
- have to do it here).
-
-However, the gratuitous load here is miniscule compared to the
-gratuitous loads of the info ptr on each enter, so we go for the first
-option.
-
--- Simon M. (6/5/96)
-
\begin{code}
-mkConCodeAndInfo :: Id -- Data constructor
+mkConCodeAndInfo :: DataCon -- Data constructor
-> (ClosureInfo, Code) -- The info table
mkConCodeAndInfo con
- = case (dataReturnConvAlg con) of
+ = let
+ arg_tys = dataConRawArgTys con
- ReturnInRegs regs ->
- let
- (closure_info, regs_w_offsets)
- = layOutDynCon con magicIdPrimRep regs
-
- body_code
- = profCtrC SLIT("RET_OLD_IN_REGS") [mkIntCLit (length regs_w_offsets)] `thenC`
-
- performReturn (mkAbstractCs (load_infoptr : map move_to_reg regs_w_offsets))
- (mkStaticAlgReturnCode con Nothing {- Info-ptr already loaded-})
- emptyIdSet{-no live vars-}
- in
- (closure_info, body_code)
-
- ReturnInHeap ->
- let
- arg_tys = dataConRawArgTys con
-
- (closure_info, arg_things)
+ (closure_info, arg_things)
= layOutDynCon con typePrimRep arg_tys
- body_code
+ body_code
= -- NB: We don't set CC when entering data (WDP 94/06)
- profCtrC SLIT("RET_OLD_IN_HEAP") [mkIntCLit (length arg_things)] `thenC`
+ profCtrC SLIT("TICK_RET_OLD")
+ [mkIntCLit (length arg_things)] `thenC`
- performReturn (mkAbstractCs [load_infoptr]) -- Ptr to thing already in Node
- (mkStaticAlgReturnCode con Nothing {- Info-ptr already loaded-})
- emptyIdSet{-no live vars-}
+ performReturn AbsCNop -- Ptr to thing already in Node
+ (mkStaticAlgReturnCode con)
in
(closure_info, body_code)
-
- where
- move_to_reg :: (MagicId, VirtualHeapOffset {-from Node-}) -> AbstractC
- move_to_reg (reg, offset)
- = CAssign (CReg reg) (CVal (NodeRel offset) (magicIdPrimRep reg))
-
- load_infoptr
- = CAssign (CReg infoptr) (CMacroExpr DataPtrRep INFO_PTR [CReg node])
\end{code}
-
-%************************************************************************
-%* *
-\subsection[CgConTbls-updates]{Generating update bits for constructors}
-%* *
-%************************************************************************
-
-Generate the "phantom" info table and update code, iff the constructor returns in regs
-
-\begin{code}
-
-genPhantomUpdInfo :: CompilationInfo -> TyCon -> Id{-data con-} -> AbstractC
-
-genPhantomUpdInfo comp_info tycon data_con
- = case (dataReturnConvAlg data_con) of
-
- ReturnInHeap -> AbsCNop -- No need for a phantom update
-
- ReturnInRegs regs ->
- let
- phantom_itbl = CClosureInfoAndCode phantom_ci AbsCNop Nothing
- upd_code con_descr
- (dataConLiveness phantom_ci)
-
- phantom_ci = layOutPhantomClosure data_con (mkConLFInfo data_con)
-
- con_descr = getOccString data_con
-
- con_arity = dataConNumFields data_con
-
- upd_code = CLabelledCode upd_label (mkAbsCStmts build_closure perform_return)
- upd_label = mkConUpdCodePtrVecLabel tycon tag
- tag = dataConTag data_con
-
- updatee = CVal (SpBRel 0 (- uF_UPDATEE)) PtrRep
-
- perform_return = mkAbstractCs
- [
- CMacroStmt POP_STD_UPD_FRAME [],
- CReturn (CReg RetReg) return_info
- ]
-
- return_info =
- case (ctrlReturnConvAlg tycon) of
- UnvectoredReturn _ -> DirectReturn
- VectoredReturn _ -> StaticVectoredReturn (tag - fIRST_TAG)
-
- -- Determine cost centre for the updated closures CC (and allocation)
- -- CCC for lexical (now your only choice)
- use_cc = CReg CurCostCentre -- what to put in the closure
- blame_cc = use_cc -- who to blame for allocation
-
- do_move (reg, virt_offset) =
- CAssign (CVal (NodeRel virt_offset) (magicIdPrimRep reg)) (CReg reg)
-
-
- -- Code for building a new constructor in place over the updatee
- overwrite_code
- = profCtrC SLIT("UPD_CON_IN_PLACE")
- [mkIntCLit (length regs_w_offsets)] `thenC`
- absC (mkAbstractCs
- [
- CAssign (CReg node) updatee,
-
- -- Tell the storage mgr that we intend to update in place
- -- This may (in complicated mgrs eg generational) cause gc,
- -- and it may modify Node to point to another place to
- -- actually update into.
- CMacroStmt upd_inplace_macro [liveness_mask],
-
- -- Initialise the closure pointed to by node
- CInitHdr closure_info (NodeRel zeroOff) use_cc True,
- mkAbstractCs (map do_move regs_w_offsets),
- if con_arity /= 0 then
- CAssign (CReg infoptr) (CLbl info_label DataPtrRep)
- else
- AbsCNop
- ])
-
- upd_inplace_macro = if closurePtrsSize closure_info == 0
- then UPD_INPLACE_NOPTRS
- else UPD_INPLACE_PTRS
-
- -- Code for allocating a new constructor in the heap
- alloc_code
- = let
- amodes_w_offsets = [ (CReg r, o) | (r,o) <- regs_w_offsets ]
- in
- -- Allocate and build closure specifying upd_new_w_regs
- allocDynClosure closure_info use_cc blame_cc amodes_w_offsets
- `thenFC` \ hp_offset ->
- getHpRelOffset hp_offset `thenFC` \ hp_rel ->
- let
- amode = CAddr hp_rel
- in
- profCtrC SLIT("UPD_CON_IN_NEW")
- [mkIntCLit (length amodes_w_offsets)] `thenC`
- absC (mkAbstractCs
- [ CMacroStmt UPD_IND [updatee, amode],
- CAssign (CReg node) amode,
- CAssign (CReg infoptr) (CLbl info_label DataPtrRep)
- ])
-
- (closure_info, regs_w_offsets) = layOutDynCon data_con magicIdPrimRep regs
- info_label = infoTableLabelFromCI closure_info
- liveness_mask = mkIntCLit (mkLiveRegsMask (node:regs))
-
- build_closure =
- if fitsMinUpdSize closure_info then
- initC comp_info overwrite_code
- else
- initC comp_info (heapCheck regs False alloc_code)
-
- in CClosureUpdInfo phantom_itbl
-
-\end{code}
-
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