2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 % $Id: CgClosure.lhs,v 1.39 2000/01/13 14:33:58 hwloidl Exp $
6 \section[CgClosure]{Code generation for closures}
8 This module provides the support code for @StgToAbstractC@ to deal
9 with {\em closures} on the RHSs of let(rec)s. See also
10 @CgCon@, which deals with constructors.
13 module CgClosure ( cgTopRhsClosure,
16 closureCodeBody ) where
18 #include "HsVersions.h"
20 import {-# SOURCE #-} CgExpr ( cgExpr )
26 import AbsCUtils ( mkAbstractCs, getAmodeRep )
27 import CgBindery ( getCAddrMode, getArgAmodes,
28 getCAddrModeAndInfo, bindNewToNode,
30 bindNewToReg, bindArgsToRegs,
31 stableAmodeIdInfo, heapIdInfo, CgIdInfo
33 import CgUpdate ( pushUpdateFrame )
34 import CgHeapery ( allocDynClosure,
35 fetchAndReschedule, yield, -- HWL
36 fastEntryChecks, thunkChecks
38 import CgStackery ( mkTaggedVirtStkOffsets, freeStackSlots )
39 import CgUsages ( adjustSpAndHp, setRealAndVirtualSp, getVirtSp,
40 getSpRelOffset, getHpRelOffset
42 import CLabel ( CLabel, mkClosureLabel, mkFastEntryLabel,
43 mkRednCountsLabel, mkInfoTableLabel,
46 import ClosureInfo -- lots and lots of stuff
47 import CmdLineOpts ( opt_GranMacros, opt_SccProfilingOn, opt_DoTickyProfiling )
49 import Id ( Id, idName, idType, idPrimRep )
50 import Name ( Name, isLocalName )
51 import Module ( Module, pprModule )
52 import ListSetOps ( minusList )
53 import PrimRep ( PrimRep(..) )
54 import PprType ( showTypeCategory )
56 import CmdLineOpts ( opt_SccProfilingOn )
59 import Name ( nameOccName )
60 import OccName ( occNameFS )
62 getWrapperArgTypeCategories = panic "CgClosure.getWrapperArgTypeCategories (ToDo)"
65 %********************************************************
67 \subsection[closures-no-free-vars]{Top-level closures}
69 %********************************************************
71 For closures bound at top level, allocate in static space.
72 They should have no free variables.
76 -> CostCentreStack -- Optional cost centre annotation
81 -> FCode (Id, CgIdInfo)
83 cgTopRhsClosure id ccs binder_info args body lf_info
84 = -- LAY OUT THE OBJECT
86 closure_info = layOutStaticNoFVClosure name lf_info
89 -- BUILD THE OBJECT (IF NECESSARY)
90 ({- if staticClosureRequired name binder_info lf_info
92 (if opt_SccProfilingOn
95 closure_label -- Labelled with the name on lhs of defn
97 (mkCCostCentreStack ccs)
101 closure_label -- Labelled with the name on lhs of defn
111 -- GENERATE THE INFO TABLE (IF NECESSARY)
112 forkClosureBody (closureCodeBody binder_info closure_info
117 returnFC (id, cg_id_info)
120 closure_label = mkClosureLabel name
121 cg_id_info = stableAmodeIdInfo id (CLbl closure_label PtrRep) lf_info
124 %********************************************************
126 \subsection[non-top-level-closures]{Non top-level closures}
128 %********************************************************
130 For closures with free vars, allocate in heap.
135 -> CostCentreStack -- Optional cost centre annotation
141 -> [StgArg] -- payload
142 -> FCode (Id, CgIdInfo)
144 cgStdRhsClosure binder cc binder_info fvs args body lf_info payload
145 -- AHA! A STANDARD-FORM THUNK
147 -- LAY OUT THE OBJECT
148 getArgAmodes payload `thenFC` \ amodes ->
150 (closure_info, amodes_w_offsets)
151 = layOutDynClosure (idName binder) getAmodeRep amodes lf_info
153 (use_cc, blame_cc) = chooseDynCostCentres cc args fvs body
156 allocDynClosure closure_info use_cc blame_cc amodes_w_offsets
158 `thenFC` \ heap_offset ->
161 returnFC (binder, heapIdInfo binder heap_offset lf_info)
164 is_std_thunk = isStandardFormThunk lf_info
167 Here's the general case.
171 -> CostCentreStack -- Optional cost centre annotation
177 -> FCode (Id, CgIdInfo)
179 cgRhsClosure binder cc binder_info fvs args body lf_info
181 -- LAY OUT THE OBJECT
183 -- If the binder is itself a free variable, then don't store
184 -- it in the closure. Instead, just bind it to Node on entry.
185 -- NB we can be sure that Node will point to it, because we
186 -- havn't told mkClosureLFInfo about this; so if the binder
187 -- *was* a free var of its RHS, mkClosureLFInfo thinks it *is*
188 -- stored in the closure itself, so it will make sure that
189 -- Node points to it...
191 is_elem = isIn "cgRhsClosure"
193 binder_is_a_fv = binder `is_elem` fvs
194 reduced_fvs = if binder_is_a_fv
195 then fvs `minusList` [binder]
198 mapFCs getCAddrModeAndInfo reduced_fvs `thenFC` \ amodes_and_info ->
200 fvs_w_amodes_and_info = reduced_fvs `zip` amodes_and_info
202 closure_info :: ClosureInfo
203 bind_details :: [((Id, (CAddrMode, LambdaFormInfo)), VirtualHeapOffset)]
205 (closure_info, bind_details)
206 = layOutDynClosure (idName binder) get_kind fvs_w_amodes_and_info lf_info
208 bind_fv ((id, (_, lf_info)), offset) = bindNewToNode id offset lf_info
210 amodes_w_offsets = [(amode,offset) | ((_, (amode,_)), offset) <- bind_details]
212 get_kind (id, amode_and_info) = idPrimRep id
214 -- BUILD ITS INFO TABLE AND CODE
217 mapCs bind_fv bind_details `thenC`
219 -- Bind the binder itself, if it is a free var
220 (if binder_is_a_fv then
221 bindNewToReg binder node lf_info
226 closureCodeBody binder_info closure_info cc args body
231 (use_cc, blame_cc) = chooseDynCostCentres cc args fvs body
233 allocDynClosure closure_info use_cc blame_cc amodes_w_offsets
234 ) `thenFC` \ heap_offset ->
237 returnFC (binder, heapIdInfo binder heap_offset lf_info)
240 %************************************************************************
242 \subsection[code-for-closures]{The code for closures}
244 %************************************************************************
247 closureCodeBody :: StgBinderInfo
248 -> ClosureInfo -- Lots of information about this closure
249 -> CostCentreStack -- Optional cost centre attached to closure
255 There are two main cases for the code for closures. If there are {\em
256 no arguments}, then the closure is a thunk, and not in normal form.
257 So it should set up an update frame (if it is shared). Also, it has
258 no argument satisfaction check, so fast and slow entry-point labels
262 closureCodeBody binder_info closure_info cc [] body
263 = -- thunks cannot have a primitive type!
264 getAbsC body_code `thenFC` \ body_absC ->
265 moduleName `thenFC` \ mod_name ->
267 absC (CClosureInfoAndCode closure_info body_absC Nothing
270 cl_descr mod_name = closureDescription mod_name (closureName closure_info)
272 body_label = entryLabelFromCI closure_info
274 is_box = case body of { StgApp fun [] -> True; _ -> False }
276 body_code = profCtrC SLIT("TICK_ENT_THK") [] `thenC`
277 thunkWrapper closure_info body_label (
278 -- We only enter cc after setting up update so that cc
279 -- of enclosing scope will be recorded in update frame
280 -- CAF/DICT functions will be subsumed by this enclosing cc
281 enterCostCentreCode closure_info cc IsThunk is_box `thenC`
285 If there is {\em at least one argument}, then this closure is in
286 normal form, so there is no need to set up an update frame. On the
287 other hand, we do have to check that there are enough args, and
288 perform an update if not!
290 The Macros for GrAnSim are produced at the beginning of the
291 argSatisfactionCheck (by calling fetchAndReschedule). There info if
292 Node points to closure is available. -- HWL
295 closureCodeBody binder_info closure_info cc all_args body
296 = getEntryConvention name lf_info
297 (map idPrimRep all_args) `thenFC` \ entry_conv ->
299 -- get the current virtual Sp (it might not be zero, eg. if we're
300 -- compiling a let-no-escape).
301 getVirtSp `thenFC` \vSp ->
304 -- Figure out what is needed and what isn't
306 -- SDM: need everything for now in case the heap/stack check refers
308 slow_code_needed = True
309 --slowFunEntryCodeRequired name binder_info entry_conv
310 info_table_needed = True
311 --funInfoTableRequired name binder_info lf_info
313 -- Arg mapping for standard (slow) entry point; all args on stack,
315 (sp_all_args, arg_offsets, arg_tags)
316 = mkTaggedVirtStkOffsets vSp idPrimRep all_args
318 -- Arg mapping for the fast entry point; as many args as poss in
319 -- registers; the rest on the stack
320 -- arg_regs are the registers used for arg passing
321 -- stk_args are the args which are passed on the stack
323 -- Args passed on the stack are tagged, but the tags may not
324 -- actually be present (just gaps) if the function is called
325 -- by jumping directly to the fast entry point.
327 arg_regs = case entry_conv of
328 DirectEntry lbl arity regs -> regs
329 other -> trace ("*** closureCodeBody:arg_regs " ++ (pprHWL entry_conv) ++ "(HWL ignored; no args passed in regs)") []
331 pprHWL :: EntryConvention -> String
332 pprHWL (ViaNode) = "ViaNode"
333 pprHWL (StdEntry cl) = "StdEntry"
334 pprHWL (DirectEntry cl i l) = "DirectEntry"
336 num_arg_regs = length arg_regs
338 (reg_args, stk_args) = splitAt num_arg_regs all_args
340 (sp_stk_args, stk_offsets, stk_tags)
341 = mkTaggedVirtStkOffsets vSp idPrimRep stk_args
343 -- HWL; Note: empty list of live regs in slow entry code
344 -- Old version (reschedule combined with heap check);
345 -- see argSatisfactionCheck for new version
346 --slow_entry_code = forceHeapCheck [node] True slow_entry_code'
347 -- where node = UnusedReg PtrRep 1
348 --slow_entry_code = forceHeapCheck [] True slow_entry_code'
351 = profCtrC SLIT("TICK_ENT_FUN_STD") [
352 CLbl ticky_ctr_label DataPtrRep
355 -- Bind args, and record expected position of stk ptrs
356 mapCs bindNewToStack arg_offsets `thenC`
357 setRealAndVirtualSp sp_all_args `thenC`
359 argSatisfactionCheck closure_info arg_regs `thenC`
361 -- OK, so there are enough args. Now we need to stuff as
362 -- many of them in registers as the fast-entry code
363 -- expects. Note that the zipWith will give up when it hits
364 -- the end of arg_regs.
366 mapFCs getCAddrMode all_args `thenFC` \ stk_amodes ->
367 absC (mkAbstractCs (zipWith assign_to_reg arg_regs stk_amodes))
370 -- Now adjust real stack pointers (no need to adjust Hp,
371 -- but call this function for convenience).
372 adjustSpAndHp sp_stk_args `thenC`
374 absC (CFallThrough (CLbl fast_label CodePtrRep))
376 assign_to_reg reg_id amode = CAssign (CReg reg_id) amode
379 -- Old version (reschedule combined with heap check);
380 -- see argSatisfactionCheck for new version
381 -- fast_entry_code = forceHeapCheck [] True fast_entry_code'
384 = moduleName `thenFC` \ mod_name ->
385 profCtrC SLIT("TICK_CTR") [
386 CLbl ticky_ctr_label DataPtrRep,
387 mkCString (_PK_ (ppr_for_ticky_name mod_name name)),
388 mkIntCLit stg_arity, -- total # of args
389 mkIntCLit sp_stk_args, -- # passed on stk
390 mkCString (_PK_ (map (showTypeCategory . idType) all_args))
393 profCtrC SLIT("TICK_ENT_FUN_DIRECT") [
394 CLbl ticky_ctr_label DataPtrRep
397 -- Nuked for now; see comment at end of file
398 -- CString (_PK_ (show_wrapper_name wrapper_maybe)),
399 -- CString (_PK_ (show_wrapper_arg_kinds wrapper_maybe))
402 -- Bind args to regs/stack as appropriate, and
403 -- record expected position of sps.
404 bindArgsToRegs reg_args arg_regs `thenC`
405 mapCs bindNewToStack stk_offsets `thenC`
406 setRealAndVirtualSp sp_stk_args `thenC`
408 -- free up the stack slots containing tags
409 freeStackSlots (map fst stk_tags) `thenC`
411 -- Enter the closures cc, if required
412 enterCostCentreCode closure_info cc IsFunction False `thenC`
415 funWrapper closure_info arg_regs stk_tags info_label (cgExpr body)
418 setTickyCtrLabel ticky_ctr_label (
420 -- Make a labelled code-block for the slow and fast entry code
421 forkAbsC (if slow_code_needed then slow_entry_code else absC AbsCNop)
422 `thenFC` \ slow_abs_c ->
423 forkAbsC fast_entry_code `thenFC` \ fast_abs_c ->
424 moduleName `thenFC` \ mod_name ->
426 -- Now either construct the info table, or put the fast code in alone
427 -- (We never have slow code without an info table)
428 -- XXX probably need the info table and slow entry code in case of
429 -- a heap check failure.
431 if info_table_needed then
432 CClosureInfoAndCode closure_info slow_abs_c (Just fast_abs_c)
435 CCodeBlock fast_label fast_abs_c
439 ticky_ctr_label = mkRednCountsLabel name
441 stg_arity = length all_args
442 lf_info = closureLFInfo closure_info
444 cl_descr mod_name = closureDescription mod_name name
446 -- Manufacture labels
447 name = closureName closure_info
448 fast_label = mkFastEntryLabel name stg_arity
449 info_label = mkInfoTableLabel name
452 -- When printing the name of a thing in a ticky file, we want to
453 -- give the module name even for *local* things. We print
454 -- just "x (M)" rather that "M.x" to distinguish them from the global kind.
455 ppr_for_ticky_name mod_name name
456 | isLocalName name = showSDocDebug (ppr name <+> (parens (ppr mod_name)))
457 | otherwise = showSDocDebug (ppr name)
460 For lexically scoped profiling we have to load the cost centre from
461 the closure entered, if the costs are not supposed to be inherited.
462 This is done immediately on entering the fast entry point.
464 Load current cost centre from closure, if not inherited.
465 Node is guaranteed to point to it, if profiling and not inherited.
468 data IsThunk = IsThunk | IsFunction -- Bool-like, local
474 :: ClosureInfo -> CostCentreStack
476 -> Bool -- is_box: this closure is a special box introduced by SCCfinal
479 enterCostCentreCode closure_info ccs is_thunk is_box
480 = if not opt_SccProfilingOn then
483 ASSERT(not (noCCSAttached ccs))
485 if isSubsumedCCS ccs then
486 ASSERT(isToplevClosure closure_info)
487 ASSERT(is_thunk == IsFunction)
488 costCentresC SLIT("ENTER_CCS_FSUB") []
490 else if isCurrentCCS ccs then
491 if re_entrant && not is_box
492 then costCentresC SLIT("ENTER_CCS_FCL") [CReg node]
493 else costCentresC SLIT("ENTER_CCS_TCL") [CReg node]
495 else if isCafCCS ccs then
496 ASSERT(isToplevClosure closure_info)
497 ASSERT(is_thunk == IsThunk)
498 -- might be a PAP, in which case we want to subsume costs
500 then costCentresC SLIT("ENTER_CCS_FSUB") []
501 else costCentresC SLIT("ENTER_CCS_CAF") c_ccs
503 else panic "enterCostCentreCode"
506 c_ccs = [mkCCostCentreStack ccs]
507 re_entrant = closureReEntrant closure_info
510 %************************************************************************
512 \subsubsection[pre-closure-code-stuff]{Pre-closure-code code}
514 %************************************************************************
516 The argument-satisfaction check code is placed after binding
517 the arguments to their stack locations. Hence, the virtual stack
518 pointer is pointing after all the args, and virtual offset 1 means
519 the base of frame and hence most distant arg. Hence
520 virtual offset 0 is just beyond the most distant argument; the
521 relative offset of this word tells how many words of arguments
525 argSatisfactionCheck :: ClosureInfo -> [MagicId] {-GRAN-} -> Code
527 argSatisfactionCheck closure_info arg_regs
529 = nodeMustPointToIt (closureLFInfo closure_info) `thenFC` \ node_points ->
532 -- emit_gran_macros = opt_GranMacros
536 -- absC (CMacroStmt GRAN_FETCH []) `thenC`
537 -- forceHeapCheck [] node_points (absC AbsCNop) `thenC`
539 -- then if node_points
540 -- then fetchAndReschedule arg_regs node_points
541 -- else yield arg_regs node_points
542 -- else absC AbsCNop) `thenC`
544 getSpRelOffset 0 `thenFC` \ (SpRel sp) ->
547 rel_arg = mkIntCLit off
551 absC (CMacroStmt ARGS_CHK [rel_arg]) -- node already points
553 absC (CMacroStmt ARGS_CHK_LOAD_NODE [rel_arg, set_Node_to_this])
555 -- We must tell the arg-satis macro whether Node is pointing to
556 -- the closure or not. If it isn't so pointing, then we give to
557 -- the macro the (static) address of the closure.
559 set_Node_to_this = CLbl (closureLabelFromCI closure_info) PtrRep
562 %************************************************************************
564 \subsubsection[closure-code-wrappers]{Wrappers around closure code}
566 %************************************************************************
569 thunkWrapper:: ClosureInfo -> CLabel -> Code -> Code
570 thunkWrapper closure_info lbl thunk_code
571 = -- Stack and heap overflow checks
572 nodeMustPointToIt (closureLFInfo closure_info) `thenFC` \ node_points ->
574 -- HWL: insert macros for GrAnSim; 2 versions depending on liveness of node
575 -- (we prefer fetchAndReschedule-style context switches to yield ones)
578 then fetchAndReschedule [] node_points
579 else yield [] node_points
580 else absC AbsCNop) `thenC`
582 -- stack and/or heap checks
583 thunkChecks lbl node_points (
585 -- Overwrite with black hole if necessary
586 blackHoleIt closure_info node_points `thenC`
588 setupUpdate closure_info ( -- setupUpdate *encloses* the rest
590 -- Finally, do the business
594 funWrapper :: ClosureInfo -- Closure whose code body this is
595 -> [MagicId] -- List of argument registers (if any)
596 -> [(VirtualSpOffset,Int)] -- tagged stack slots
597 -> CLabel -- info table for heap check ret.
598 -> Code -- Body of function being compiled
600 funWrapper closure_info arg_regs stk_tags info_label fun_body
601 = -- Stack overflow check
602 nodeMustPointToIt (closureLFInfo closure_info) `thenFC` \ node_points ->
605 then yield arg_regs node_points
606 else absC AbsCNop) `thenC`
608 -- heap and/or stack checks
609 fastEntryChecks arg_regs stk_tags info_label node_points (
611 -- Finally, do the business
617 %************************************************************************
619 \subsubsubsection[update-and-BHs]{Update and black-hole wrappers}
621 %************************************************************************
625 blackHoleIt :: ClosureInfo -> Bool -> Code -- Only called for closures with no args
627 blackHoleIt closure_info node_points
628 = if blackHoleOnEntry closure_info && node_points
631 info_label = infoTableLabelFromCI closure_info
632 args = [ CLbl info_label DataPtrRep ]
634 absC (if closureSingleEntry(closure_info) then
635 CMacroStmt UPD_BH_SINGLE_ENTRY args
637 CMacroStmt UPD_BH_UPDATABLE args)
643 setupUpdate :: ClosureInfo -> Code -> Code -- Only called for closures with no args
644 -- Nota Bene: this function does not change Node (even if it's a CAF),
645 -- so that the cost centre in the original closure can still be
646 -- extracted by a subsequent ENTER_CC_TCL
648 -- I've tidied up the code for this function, but it should still do the same as
649 -- it did before (modulo ticky stuff). KSW 1999-04.
650 setupUpdate closure_info code
651 = if closureReEntrant closure_info
655 case (closureUpdReqd closure_info, isStaticClosure closure_info) of
656 (False,False) -> profCtrC SLIT("TICK_UPDF_OMITTED") [] `thenC`
658 (False,True ) -> (if opt_DoTickyProfiling
660 -- blackhole the SE CAF
661 link_caf seCafBlackHoleClosureInfo `thenFC` \ _ -> nopC
664 profCtrC SLIT("TICK_UPD_CAF_BH_SINGLE_ENTRY") [mkCString cl_name] `thenC`
665 profCtrC SLIT("TICK_UPDF_OMITTED") [] `thenC`
667 (True ,False) -> pushUpdateFrame (CReg node) code
668 (True ,True ) -> -- blackhole the (updatable) CAF:
669 link_caf cafBlackHoleClosureInfo `thenFC` \ update_closure ->
670 profCtrC SLIT("TICK_UPD_CAF_BH_UPDATABLE") [mkCString cl_name] `thenC`
671 pushUpdateFrame update_closure code
673 cl_name :: FAST_STRING
674 cl_name = (occNameFS . nameOccName . closureName) closure_info
676 link_caf :: (ClosureInfo -> ClosureInfo) -- function yielding BH closure_info
677 -> FCode CAddrMode -- Returns amode for closure to be updated
679 = -- To update a CAF we must allocate a black hole, link the CAF onto the
680 -- CAF list, then update the CAF to point to the fresh black hole.
681 -- This function returns the address of the black hole, so it can be
682 -- updated with the new value when available.
684 -- Alloc black hole specifying CC_HDR(Node) as the cost centre
685 -- Hack Warning: Using a CLitLit to get CAddrMode !
687 use_cc = CLitLit SLIT("CCS_HDR(R1.p)") PtrRep
690 allocDynClosure (bhCI closure_info) use_cc blame_cc [] `thenFC` \ heap_offset ->
691 getHpRelOffset heap_offset `thenFC` \ hp_rel ->
692 let amode = CAddr hp_rel
694 absC (CMacroStmt UPD_CAF [CReg node, amode]) `thenC`
698 %************************************************************************
700 \subsection[CgClosure-Description]{Profiling Closure Description.}
702 %************************************************************************
704 For "global" data constructors the description is simply occurrence
705 name of the data constructor itself (see \ref{CgConTbls-info-tables}).
707 Otherwise it is determind by @closureDescription@ from the let
711 closureDescription :: Module -- Module
712 -> Name -- Id of closure binding
715 -- Not called for StgRhsCon which have global info tables built in
716 -- CgConTbls.lhs with a description generated from the data constructor
718 closureDescription mod_name name
728 chooseDynCostCentres ccs args fvs body
730 use_cc -- cost-centre we record in the object
731 = if currentOrSubsumedCCS ccs
732 then CReg CurCostCentre
733 else mkCCostCentreStack ccs
735 blame_cc -- cost-centre on whom we blame the allocation
736 = case (args, fvs, body) of
737 ([], _, StgApp fun [{-no args-}])
738 -> mkCCostCentreStack overheadCCS
741 -- if it's an utterly trivial RHS, then it must be
742 -- one introduced by boxHigherOrderArgs for profiling,
743 -- so we charge it to "OVERHEAD".
745 -- This looks like a HACK to me --SDM
752 ========================================================================
753 OLD CODE THAT EMITTED INFORMATON FOR QUANTITATIVE ANALYSIS
755 It's pretty wierd, so I've nuked it for now. SLPJ Nov 96
758 getWrapperArgTypeCategories
759 :: Type -- wrapper's type
760 -> StrictnessInfo bdee -- strictness info about its args
763 getWrapperArgTypeCategories _ NoStrictnessInfo = Nothing
764 getWrapperArgTypeCategories _ BottomGuaranteed
765 = trace "getWrapperArgTypeCategories:BottomGuaranteed!" Nothing -- wrong
766 getWrapperArgTypeCategories _ (StrictnessInfo [] _) = Nothing
768 getWrapperArgTypeCategories ty (StrictnessInfo arg_info _)
769 = Just (mkWrapperArgTypeCategories ty arg_info)
771 mkWrapperArgTypeCategories
772 :: Type -- wrapper's type
773 -> [Demand] -- info about its arguments
774 -> String -- a string saying lots about the args
776 mkWrapperArgTypeCategories wrapper_ty wrap_info
777 = case (splitFunTy_maybe wrapper_ty) of { Just (arg_tys,_) ->
778 map do_one (wrap_info `zip` (map showTypeCategory arg_tys)) }
780 -- ToDo: this needs FIXING UP (it was a hack anyway...)
781 do_one (WwPrim, _) = 'P'
782 do_one (WwEnum, _) = 'E'
783 do_one (WwStrict, arg_ty_char) = arg_ty_char
784 do_one (WwUnpack _ _ _, arg_ty_char)
785 = if arg_ty_char `elem` "CIJFDTS"
786 then toLower arg_ty_char
787 else if arg_ty_char == '+' then 't'
788 else trace ("mkWrapp..:funny char:"++[arg_ty_char]) '-'
789 do_one (other_wrap_info, _) = '-'