2 % (c) The University of Glasgow 2000
4 \section[ByteCodeGen]{Generate bytecode from Core}
7 module ByteCodeGen ( UnlinkedBCO, UnlinkedBCOExpr, ItblEnv, ClosureEnv, HValue,
9 byteCodeGen, coreExprToBCOs
12 #include "HsVersions.h"
15 import Name ( Name, getName )
16 import Id ( Id, idType, isDataConId_maybe, isPrimOpId_maybe, isFCallId,
17 idPrimRep, mkSysLocal, idName, isFCallId_maybe, isPrimOpId )
18 import ForeignCall ( ForeignCall(..), CCallTarget(..), CCallSpec(..) )
19 import OrdList ( OrdList, consOL, snocOL, appOL, unitOL,
20 nilOL, toOL, concatOL, fromOL )
21 import FiniteMap ( FiniteMap, addListToFM, listToFM, elemFM,
22 addToFM, lookupFM, fmToList )
24 import PprCore ( pprCoreExpr )
25 import Literal ( Literal(..), literalPrimRep )
26 import PrimRep ( PrimRep(..) )
27 import PrimOp ( PrimOp(..) )
28 import CoreFVs ( freeVars )
29 import Type ( typePrimRep, splitTyConApp_maybe, isTyVarTy )
30 import DataCon ( dataConTag, fIRST_TAG, dataConTyCon,
31 dataConWrapId, isUnboxedTupleCon )
32 import TyCon ( TyCon(..), tyConFamilySize, isDataTyCon, tyConDataCons,
33 isFunTyCon, isUnboxedTupleTyCon )
34 import Class ( Class, classTyCon )
35 import Type ( Type, repType, splitRepFunTys )
36 import Util ( zipEqual, zipWith4Equal, naturalMergeSortLe, nOfThem,
37 isSingleton, lengthIs )
38 import DataCon ( dataConRepArity )
39 import Var ( isTyVar )
40 import VarSet ( VarSet, varSetElems )
41 import PrimRep ( isFollowableRep )
42 import CmdLineOpts ( DynFlags, DynFlag(..) )
43 import ErrUtils ( showPass, dumpIfSet_dyn )
44 import Unique ( mkPseudoUnique3 )
45 import FastString ( FastString(..) )
46 import Panic ( GhcException(..) )
47 import PprType ( pprType )
48 import SMRep ( arrWordsHdrSize, arrPtrsHdrSize )
49 import Constants ( wORD_SIZE )
50 import ByteCodeInstr ( BCInstr(..), ProtoBCO(..), nameOfProtoBCO, bciStackUse )
51 import ByteCodeItbls ( ItblEnv, mkITbls )
52 import ByteCodeLink ( UnlinkedBCO, UnlinkedBCOExpr, assembleBCO,
53 ClosureEnv, HValue, filterNameMap, linkFail,
54 iNTERP_STACK_CHECK_THRESH )
55 import ByteCodeFFI ( taggedSizeW, untaggedSizeW, mkMarshalCode, moan64 )
56 import Linker ( lookupSymbol )
58 import List ( intersperse, sortBy, zip4 )
59 import Foreign ( Ptr(..), castPtr, mallocBytes, pokeByteOff, Word8 )
60 import CTypes ( CInt )
61 import Exception ( throwDyn )
63 import GlaExts ( Int(..), ByteArray# )
66 import Maybe ( isJust )
70 %************************************************************************
72 \subsection{Functions visible from outside this module.}
74 %************************************************************************
78 byteCodeGen :: DynFlags
81 -> IO ([UnlinkedBCO], ItblEnv)
82 byteCodeGen dflags binds local_tycons local_classes
83 = do showPass dflags "ByteCodeGen"
84 let tycs = local_tycons ++ map classTyCon local_classes
85 itblenv <- mkITbls tycs
87 let flatBinds = concatMap getBind binds
88 getBind (NonRec bndr rhs) = [(bndr, freeVars rhs)]
89 getBind (Rec binds) = [(bndr, freeVars rhs) | (bndr,rhs) <- binds]
91 (BcM_State proto_bcos final_ctr mallocd, ())
92 <- runBc (BcM_State [] 0 [])
93 (mapBc (schemeR True []) flatBinds `thenBc_` returnBc ())
95 -- better be no free vars in these top-level bindings
97 when (not (null mallocd))
98 (panic "ByteCodeGen.byteCodeGen: missing final emitBc?")
100 dumpIfSet_dyn dflags Opt_D_dump_BCOs
101 "Proto-bcos" (vcat (intersperse (char ' ') (map ppr proto_bcos)))
103 bcos <- mapM assembleBCO proto_bcos
105 return (bcos, itblenv)
108 -- Returns: (the root BCO for this expression,
109 -- a list of auxilary BCOs resulting from compiling closures)
110 coreExprToBCOs :: DynFlags
112 -> IO UnlinkedBCOExpr
113 coreExprToBCOs dflags expr
114 = do showPass dflags "ByteCodeGen"
116 -- create a totally bogus name for the top-level BCO; this
117 -- should be harmless, since it's never used for anything
118 let invented_id = mkSysLocal SLIT("Expr-Top-Level") (mkPseudoUnique3 0)
119 (panic "invented_id's type")
120 let invented_name = idName invented_id
122 annexpr = freeVars expr
123 fvs = filter (not.isTyVar) (varSetElems (fst annexpr))
125 (BcM_State all_proto_bcos final_ctr mallocd, ())
126 <- runBc (BcM_State [] 0 [])
127 (schemeR True fvs (invented_id, annexpr))
129 when (not (null mallocd))
130 (panic "ByteCodeGen.coreExprToBCOs: missing final emitBc?")
132 dumpIfSet_dyn dflags Opt_D_dump_BCOs
133 "Proto-bcos" (vcat (intersperse (char ' ') (map ppr all_proto_bcos)))
136 = case filter ((== invented_name).nameOfProtoBCO) all_proto_bcos of
137 [root_bco] -> root_bco
139 = filter ((/= invented_name).nameOfProtoBCO) all_proto_bcos
141 auxiliary_bcos <- mapM assembleBCO auxiliary_proto_bcos
142 root_bco <- assembleBCO root_proto_bco
144 return (root_bco, auxiliary_bcos)
147 %************************************************************************
149 \subsection{Compilation schema for the bytecode generator.}
151 %************************************************************************
155 type BCInstrList = OrdList BCInstr
157 type Sequel = Int -- back off to this depth before ENTER
159 -- Maps Ids to the offset from the stack _base_ so we don't have
160 -- to mess with it after each push/pop.
161 type BCEnv = FiniteMap Id Int -- To find vars on the stack
163 ppBCEnv :: BCEnv -> SDoc
166 $$ nest 4 (vcat (map pp_one (sortBy cmp_snd (fmToList p))))
169 pp_one (var, offset) = int offset <> colon <+> ppr var
170 cmp_snd x y = compare (snd x) (snd y)
172 -- Create a BCO and do a spot of peephole optimisation on the insns
174 mkProtoBCO nm instrs_ordlist origin mallocd_blocks
175 = ProtoBCO nm maybe_with_stack_check origin mallocd_blocks
177 -- Overestimate the stack usage (in words) of this BCO,
178 -- and if >= iNTERP_STACK_CHECK_THRESH, add an explicit
179 -- stack check. (The interpreter always does a stack check
180 -- for iNTERP_STACK_CHECK_THRESH words at the start of each
181 -- BCO anyway, so we only need to add an explicit on in the
182 -- (hopefully rare) cases when the (overestimated) stack use
183 -- exceeds iNTERP_STACK_CHECK_THRESH.
184 maybe_with_stack_check
185 | stack_overest >= 65535
186 = pprPanic "mkProtoBCO: stack use won't fit in 16 bits"
188 | stack_overest >= iNTERP_STACK_CHECK_THRESH
189 = (STKCHECK stack_overest) : peep_d
191 = peep_d -- the supposedly common case
193 stack_overest = sum (map bciStackUse peep_d)
194 + 10 {- just to be really really sure -}
197 -- Merge local pushes
198 peep_d = peep (fromOL instrs_ordlist)
200 peep (PUSH_L off1 : PUSH_L off2 : PUSH_L off3 : rest)
201 = PUSH_LLL off1 (off2-1) (off3-2) : peep rest
202 peep (PUSH_L off1 : PUSH_L off2 : rest)
203 = PUSH_LL off1 (off2-1) : peep rest
210 -- Compile code for the right hand side of a let binding.
211 -- Park the resulting BCO in the monad. Also requires the
212 -- variable to which this value was bound, so as to give the
213 -- resulting BCO a name. Bool indicates top-levelness.
215 schemeR :: Bool -> [Id] -> (Id, AnnExpr Id VarSet) -> BcM ()
216 schemeR is_top fvs (nm, rhs)
220 $$ (ppr.filter (not.isTyVar).varSetElems.fst) rhs
221 $$ pprCoreExpr (deAnnotate rhs)
227 = schemeR_wrk is_top fvs rhs nm (collect [] rhs)
230 collect xs (_, AnnNote note e)
232 collect xs (_, AnnLam x e)
233 = collect (if isTyVar x then xs else (x:xs)) e
234 collect xs not_lambda
235 = (reverse xs, not_lambda)
237 schemeR_wrk is_top fvs original_body nm (args, body)
238 | Just dcon <- maybe_toplevel_null_con_rhs
239 = --trace ("nullary constructor! " ++ showSDocDebug (ppr nm)) (
240 emitBc (mkProtoBCO (getName nm) (toOL [PACK dcon 0, ENTER])
241 (Right original_body))
245 = let all_args = reverse args ++ fvs
246 szsw_args = map taggedIdSizeW all_args
247 szw_args = sum szsw_args
248 p_init = listToFM (zip all_args (mkStackOffsets 0 szsw_args))
249 argcheck = unitOL (ARGCHECK szw_args)
251 schemeE szw_args 0 p_init body `thenBc` \ body_code ->
252 emitBc (mkProtoBCO (getName nm) (appOL argcheck body_code)
253 (Right original_body))
256 maybe_toplevel_null_con_rhs
257 | is_top && null args
258 = case nukeTyArgs (snd body) of
260 -> case isDataConId_maybe v_wrk of
262 Just dc_wrk | nm == dataConWrapId dc_wrk
270 nukeTyArgs (AnnApp f (_, AnnType _)) = nukeTyArgs (snd f)
271 nukeTyArgs other = other
274 -- Let szsw be the sizes in words of some items pushed onto the stack,
275 -- which has initial depth d'. Return the values which the stack environment
276 -- should map these items to.
277 mkStackOffsets :: Int -> [Int] -> [Int]
278 mkStackOffsets original_depth szsw
279 = map (subtract 1) (tail (scanl (+) original_depth szsw))
281 -- Compile code to apply the given expression to the remaining args
282 -- on the stack, returning a HNF.
283 schemeE :: Int -> Sequel -> BCEnv -> AnnExpr Id VarSet -> BcM BCInstrList
285 -- Delegate tail-calls to schemeT.
286 schemeE d s p e@(fvs, AnnApp f a)
287 = schemeT d s p (fvs, AnnApp f a)
289 schemeE d s p e@(fvs, AnnVar v)
290 | isFollowableRep v_rep
291 = -- Ptr-ish thing; push it in the normal way
292 schemeT d s p (fvs, AnnVar v)
295 = -- returning an unboxed value. Heave it on the stack, SLIDE, and RETURN.
296 pushAtom True d p (AnnVar v) `thenBc` \ (push, szw) ->
297 returnBc (push -- value onto stack
298 `appOL` mkSLIDE szw (d-s) -- clear to sequel
299 `snocOL` RETURN v_rep) -- go
301 v_rep = typePrimRep (idType v)
303 schemeE d s p (fvs, AnnLit literal)
304 = pushAtom True d p (AnnLit literal) `thenBc` \ (push, szw) ->
305 let l_rep = literalPrimRep literal
306 in returnBc (push -- value onto stack
307 `appOL` mkSLIDE szw (d-s) -- clear to sequel
308 `snocOL` RETURN l_rep) -- go
312 Deal specially with the cases
313 let x = fn atom1 .. atomn in B
315 let x = Con atom1 .. atomn in B
316 (Con must be saturated)
318 In these cases, generate code to allocate in-line.
320 This is optimisation of the general case for let, which follows
321 this one; this case can safely be omitted. The reduction in
322 interpreter execution time seems to be around 5% for some programs,
323 with a similar drop in allocations.
325 This optimisation should be done more cleanly. As-is, it is
326 inapplicable to RHSs in letrecs, and needlessly duplicates code in
327 schemeR and schemeT. Some refactoring of the machinery would cure
330 schemeE d s p ee@(fvs, AnnLet (AnnNonRec x rhs) b)
332 = let d_init = if is_con then d else d'
334 mkPushes d_init args_r_to_l_reordered `thenBc` \ (d_final, push_code) ->
335 schemeE d' s p' b `thenBc` \ body_code ->
336 let size = d_final - d_init
337 alloc = if is_con then nilOL else unitOL (ALLOC size)
338 pack = unitOL (if is_con then PACK the_dcon size else MKAP size size)
340 returnBc (alloc `appOL` push_code `appOL` pack
343 -- Decide whether we can do this or not
344 (ok_to_go, is_con, the_dcon, the_fn)
346 Nothing -> (False, bomb 1, bomb 2, bomb 3)
347 Just (Left fn) -> (True, False, bomb 5, fn)
349 | dataConRepArity dcon <= length args_r_to_l
350 -> (True, True, dcon, bomb 6)
352 -> (False, bomb 7, bomb 8, bomb 9)
353 bomb n = panic ("schemeE.is_con(hacky hack hack) " ++ show n)
355 -- Extract the args (R -> L) and fn
356 args_r_to_l_reordered
360 = filter (not.isPtr.snd) args_r_to_l ++ filter (isPtr.snd) args_r_to_l
361 where isPtr = isFollowableRep . atomRep
363 args_r_to_l = filter (not.isTypeAtom.snd) args_r_to_l_raw
364 isTypeAtom (AnnType _) = True
367 (args_r_to_l_raw, maybe_fn) = chomp rhs
371 | isFCallId v || isPrimOpId v
374 -> case isDataConId_maybe v of
375 Just dcon -> ([], Just (Right dcon))
376 Nothing -> ([], Just (Left v))
377 AnnApp f a -> case chomp f of (az, f) -> (a:az, f)
378 AnnNote n e -> chomp e
379 other -> ([], Nothing)
381 -- This is the env in which to translate the body
385 -- Shove the args on the stack, including the fn in the non-dcon case
386 tag_when_push = not is_con
388 mkPushes :: Int{-curr depth-} -> [AnnExpr Id VarSet]
389 -> BcM (Int{-final depth-}, BCInstrList)
392 = returnBc (dd, nilOL)
394 = pushAtom False dd p' (AnnVar the_fn) `thenBc` \ (fn_push_code, fn_szw) ->
395 returnBc (dd+fn_szw, fn_push_code)
396 mkPushes dd (atom:atoms)
397 = pushAtom tag_when_push dd p' (snd atom)
398 `thenBc` \ (push1_code, push1_szw) ->
399 mkPushes (dd+push1_szw) atoms `thenBc` \ (dd_final, push_rest) ->
400 returnBc (dd_final, push1_code `appOL` push_rest)
403 -- General case for let. Generates correct, if inefficient, code in
405 schemeE d s p (fvs, AnnLet binds b)
406 = let (xs,rhss) = case binds of AnnNonRec x rhs -> ([x],[rhs])
407 AnnRec xs_n_rhss -> unzip xs_n_rhss
410 is_local id = not (isTyVar id) && elemFM id p'
411 fvss = map (filter is_local . varSetElems . fst) rhss
413 -- Sizes of tagged free vars, + 1 for the fn
414 sizes = map (\rhs_fvs -> 1 + sum (map taggedIdSizeW rhs_fvs)) fvss
416 -- This p', d' defn is safe because all the items being pushed
417 -- are ptrs, so all have size 1. d' and p' reflect the stack
418 -- after the closures have been allocated in the heap (but not
419 -- filled in), and pointers to them parked on the stack.
420 p' = addListToFM p (zipE xs (mkStackOffsets d (nOfThem n 1)))
423 infos = zipE4 fvss sizes xs [n, n-1 .. 1]
424 zipE = zipEqual "schemeE"
425 zipE4 = zipWith4Equal "schemeE" (\a b c d -> (a,b,c,d))
427 -- ToDo: don't build thunks for things with no free variables
428 buildThunk dd ([], size, id, off)
429 = returnBc (PUSH_G (Left (getName id))
430 `consOL` unitOL (MKAP (off+size-1) size))
431 buildThunk dd ((fv:fvs), size, id, off)
432 = pushAtom True dd p' (AnnVar fv)
433 `thenBc` \ (push_code, pushed_szw) ->
434 buildThunk (dd+pushed_szw) (fvs, size, id, off)
435 `thenBc` \ more_push_code ->
436 returnBc (push_code `appOL` more_push_code)
438 genThunkCode = mapBc (buildThunk d') infos `thenBc` \ tcodes ->
439 returnBc (concatOL tcodes)
441 allocCode = toOL (map ALLOC sizes)
443 schemeRs [] _ _ = returnBc ()
444 schemeRs (fvs:fvss) (x:xs) (rhs:rhss) =
445 schemeR False fvs (x,rhs) `thenBc_` schemeRs fvss xs rhss
447 schemeE d' s p' b `thenBc` \ bodyCode ->
448 schemeRs fvss xs rhss `thenBc_`
449 genThunkCode `thenBc` \ thunkCode ->
450 returnBc (allocCode `appOL` thunkCode `appOL` bodyCode)
456 schemeE d s p (fvs_case, AnnCase (fvs_scrut, scrut) bndr
457 [(DEFAULT, [], (fvs_rhs, rhs))])
459 | let isFunType var_type
460 = case splitTyConApp_maybe var_type of
461 Just (tycon,_) | isFunTyCon tycon -> True
463 ty_bndr = repType (idType bndr)
464 in isFunType ty_bndr || isTyVarTy ty_bndr
467 -- case scrut::suspect of bndr { DEFAULT -> rhs }
469 -- let bndr = scrut in rhs
470 -- when suspect is polymorphic or arrowtyped
471 -- So the required strictness properties are not observed.
472 -- At some point, must fix this properly.
476 (AnnNonRec bndr (fvs_scrut, scrut)) (fvs_rhs, rhs)
479 in trace ("WARNING: ignoring polymorphic case in interpreted mode.\n" ++
480 " Possibly due to strict polymorphic/functional constructor args.\n" ++
481 " Your program may leak space unexpectedly.\n")
482 (schemeE d s p new_expr)
486 {- Convert case .... of (# VoidRep'd-thing, a #) -> ...
488 case .... of a -> ...
489 Use a as the name of the binder too.
491 Also case .... of (# a #) -> ...
493 case .... of a -> ...
495 schemeE d s p (fvs, AnnCase scrut bndr [(DataAlt dc, [bind1, bind2], rhs)])
496 | isUnboxedTupleCon dc && VoidRep == typePrimRep (idType bind1)
497 = --trace "automagic mashing of case alts (# VoidRep, a #)" (
498 schemeE d s p (fvs, AnnCase scrut bind2 [(DEFAULT, [bind2], rhs)])
501 schemeE d s p (fvs, AnnCase scrut bndr [(DataAlt dc, [bind1], rhs)])
502 | isUnboxedTupleCon dc
503 = --trace "automagic mashing of case alts (# a #)" (
504 schemeE d s p (fvs, AnnCase scrut bind1 [(DEFAULT, [bind1], rhs)])
507 schemeE d s p (fvs, AnnCase scrut bndr alts)
509 -- Top of stack is the return itbl, as usual.
510 -- underneath it is the pointer to the alt_code BCO.
511 -- When an alt is entered, it assumes the returned value is
512 -- on top of the itbl.
515 -- Env and depth in which to compile the alts, not including
516 -- any vars bound by the alts themselves
517 d' = d + ret_frame_sizeW + taggedIdSizeW bndr
518 p' = addToFM p bndr (d' - 1)
520 scrut_primrep = typePrimRep (idType bndr)
522 | scrut_primrep == PtrRep
524 | scrut_primrep `elem`
525 [CharRep, AddrRep, WordRep, IntRep, FloatRep, DoubleRep,
526 VoidRep, Int8Rep, Int16Rep, Int32Rep, Int64Rep,
527 Word8Rep, Word16Rep, Word32Rep, Word64Rep]
530 = pprPanic "ByteCodeGen.schemeE" (ppr scrut_primrep)
532 -- given an alt, return a discr and code for it.
533 codeAlt alt@(discr, binds_f, rhs)
535 = let (unpack_code, d_after_unpack, p_after_unpack)
536 = mkUnpackCode (filter (not.isTyVar) binds_f) d' p'
537 in schemeE d_after_unpack s p_after_unpack rhs
538 `thenBc` \ rhs_code ->
539 returnBc (my_discr alt, unpack_code `appOL` rhs_code)
541 = ASSERT(null binds_f)
542 schemeE d' s p' rhs `thenBc` \ rhs_code ->
543 returnBc (my_discr alt, rhs_code)
545 my_discr (DEFAULT, binds, rhs) = NoDiscr
546 my_discr (DataAlt dc, binds, rhs)
547 | isUnboxedTupleCon dc
548 = unboxedTupleException
550 = DiscrP (dataConTag dc - fIRST_TAG)
551 my_discr (LitAlt l, binds, rhs)
552 = case l of MachInt i -> DiscrI (fromInteger i)
553 MachFloat r -> DiscrF (fromRational r)
554 MachDouble r -> DiscrD (fromRational r)
555 MachChar i -> DiscrI i
556 _ -> pprPanic "schemeE(AnnCase).my_discr" (ppr l)
559 | not isAlgCase = Nothing
561 = case [dc | (DataAlt dc, _, _) <- alts] of
563 (dc:_) -> Just (tyConFamilySize (dataConTyCon dc))
566 mapBc codeAlt alts `thenBc` \ alt_stuff ->
567 mkMultiBranch maybe_ncons alt_stuff `thenBc` \ alt_final ->
569 alt_final_ac = ARGCHECK (taggedIdSizeW bndr) `consOL` alt_final
570 alt_bco_name = getName bndr
571 alt_bco = mkProtoBCO alt_bco_name alt_final_ac (Left alts)
573 schemeE (d + ret_frame_sizeW)
574 (d + ret_frame_sizeW) p scrut `thenBc` \ scrut_code ->
576 emitBc alt_bco `thenBc_`
577 returnBc (PUSH_AS alt_bco_name scrut_primrep `consOL` scrut_code)
580 schemeE d s p (fvs, AnnNote note body)
584 = pprPanic "ByteCodeGen.schemeE: unhandled case"
585 (pprCoreExpr (deAnnotate other))
588 -- Compile code to do a tail call. Specifically, push the fn,
589 -- slide the on-stack app back down to the sequel depth,
590 -- and enter. Four cases:
593 -- An application "PrelGHC.tagToEnum# <type> unboxed-int".
594 -- The int will be on the stack. Generate a code sequence
595 -- to convert it to the relevant constructor, SLIDE and ENTER.
597 -- 1. A nullary constructor. Push its closure on the stack
598 -- and SLIDE and RETURN.
600 -- 2. (Another nasty hack). Spot (# a::VoidRep, b #) and treat
601 -- it simply as b -- since the representations are identical
602 -- (the VoidRep takes up zero stack space). Also, spot
603 -- (# b #) and treat it as b.
605 -- 3. The fn denotes a ccall. Defer to generateCCall.
607 -- 4. Application of a non-nullary constructor, by defn saturated.
608 -- Split the args into ptrs and non-ptrs, and push the nonptrs,
609 -- then the ptrs, and then do PACK and RETURN.
611 -- 5. Otherwise, it must be a function call. Push the args
612 -- right to left, SLIDE and ENTER.
614 schemeT :: Int -- Stack depth
615 -> Sequel -- Sequel depth
616 -> BCEnv -- stack env
622 -- | trace ("schemeT: env in = \n" ++ showSDocDebug (ppBCEnv p)) False
623 -- = panic "schemeT ?!?!"
625 -- | trace ("\nschemeT\n" ++ showSDoc (pprCoreExpr (deAnnotate app)) ++ "\n") False
629 | Just (arg, constr_names) <- maybe_is_tagToEnum_call
630 = pushAtom True d p arg `thenBc` \ (push, arg_words) ->
631 implement_tagToId constr_names `thenBc` \ tagToId_sequence ->
632 returnBc (push `appOL` tagToId_sequence
633 `appOL` mkSLIDE 1 (d+arg_words-s)
637 | is_con_call && null args_r_to_l
639 (PUSH_G (Left (getName con)) `consOL` mkSLIDE 1 (d-s))
644 | let isVoidRepAtom (_, AnnVar v) = VoidRep == typePrimRep (idType v)
645 isVoidRepAtom (_, AnnNote n e) = isVoidRepAtom e
646 in is_con_call && isUnboxedTupleCon con
647 && ( (args_r_to_l `lengthIs` 2 && isVoidRepAtom (last (args_r_to_l)))
648 || (isSingleton args_r_to_l)
650 = --trace (if isSingleton args_r_to_l
651 -- then "schemeT: unboxed singleton"
652 -- else "schemeT: unboxed pair with Void first component") (
653 schemeT d s p (head args_r_to_l)
657 | Just (CCall ccall_spec) <- isFCallId_maybe fn
658 = generateCCall d s p ccall_spec fn args_r_to_l
662 = if is_con_call && isUnboxedTupleCon con
663 then unboxedTupleException
664 else do_pushery d (map snd args_final_r_to_l)
667 -- Detect and extract relevant info for the tagToEnum kludge.
668 maybe_is_tagToEnum_call
669 = let extract_constr_Names ty
670 = case splitTyConApp_maybe (repType ty) of
671 (Just (tyc, [])) | isDataTyCon tyc
672 -> map getName (tyConDataCons tyc)
673 other -> panic "maybe_is_tagToEnum_call.extract_constr_Ids"
676 (_, AnnApp (_, AnnApp (_, AnnVar v) (_, AnnType t)) arg)
677 -> case isPrimOpId_maybe v of
678 Just TagToEnumOp -> Just (snd arg, extract_constr_Names t)
682 -- Extract the args (R->L) and fn
683 (args_r_to_l, fn) = chomp app
688 | isTypeAtom (snd a) -> chomp f
689 | otherwise -> case chomp f of (az, f) -> (a:az, f)
690 AnnNote n e -> chomp e
691 other -> pprPanic "schemeT"
692 (ppr (deAnnotate (panic "schemeT.chomp", other)))
694 n_args = length args_r_to_l
696 isTypeAtom (AnnType _) = True
699 -- decide if this is a constructor application, because we need
700 -- to rearrange the arguments on the stack if so. For building
701 -- a constructor, we put pointers before non-pointers and omit
704 -- Also if the constructor is not saturated, we just arrange to
705 -- call the curried worker instead.
707 maybe_dcon = case isDataConId_maybe fn of
708 Just con | dataConRepArity con == n_args -> Just con
710 is_con_call = isJust maybe_dcon
711 (Just con) = maybe_dcon
717 = filter (not.isPtr.snd) args_r_to_l ++ filter (isPtr.snd) args_r_to_l
718 where isPtr = isFollowableRep . atomRep
720 -- make code to push the args and then do the SLIDE-ENTER thing
721 tag_when_push = not is_con_call
722 narg_words = sum (map (get_arg_szw . atomRep . snd) args_r_to_l)
723 get_arg_szw = if tag_when_push then taggedSizeW else untaggedSizeW
725 do_pushery d (arg:args)
726 = pushAtom tag_when_push d p arg `thenBc` \ (push, arg_words) ->
727 do_pushery (d+arg_words) args `thenBc` \ more_push_code ->
728 returnBc (push `appOL` more_push_code)
730 | Just (CCall ccall_spec) <- isFCallId_maybe fn
731 = panic "schemeT.do_pushery: unexpected ccall"
734 Just con -> returnBc (
735 (PACK con narg_words `consOL`
736 mkSLIDE 1 (d - narg_words - s)) `snocOL`
740 -> pushAtom True d p (AnnVar fn)
741 `thenBc` \ (push, arg_words) ->
742 returnBc (push `appOL` mkSLIDE (narg_words+arg_words)
747 {- Deal with a CCall. Taggedly push the args onto the stack R->L,
748 deferencing ForeignObj#s and (ToDo: adjusting addrs to point to
749 payloads in Ptr/Byte arrays). Then, generate the marshalling
750 (machine) code for the ccall, and create bytecodes to call that and
751 then return in the right way.
753 generateCCall :: Int -> Sequel -- stack and sequel depths
755 -> CCallSpec -- where to call
756 -> Id -- of target, for type info
757 -> [AnnExpr Id VarSet] -- args (atoms)
760 generateCCall d0 s p ccall_spec@(CCallSpec target cconv safety) fn args_r_to_l
763 addr_usizeW = untaggedSizeW AddrRep
764 addr_tsizeW = taggedSizeW AddrRep
766 -- Get the args on the stack, with tags and suitably
767 -- dereferenced for the CCall. For each arg, return the
768 -- depth to the first word of the bits for that arg, and the
769 -- PrimRep of what was actually pushed.
771 pargs d [] = returnBc []
773 = let rep_arg = atomRep a
775 -- Don't push the FO; instead push the Addr# it
778 -> pushAtom False{-irrelevant-} d p a
779 `thenBc` \ (push_fo, _) ->
780 let foro_szW = taggedSizeW ForeignObjRep
781 d_now = d + addr_tsizeW
782 code = push_fo `appOL` toOL [
783 UPK_TAG addr_usizeW 0 0,
784 SLIDE addr_tsizeW foro_szW
786 in pargs d_now az `thenBc` \ rest ->
787 returnBc ((code, AddrRep) : rest)
790 -> pargs (d + addr_tsizeW) az `thenBc` \ rest ->
791 parg_ArrayishRep arrPtrsHdrSize d p a
793 returnBc ((code,AddrRep):rest)
796 -> pargs (d + addr_tsizeW) az `thenBc` \ rest ->
797 parg_ArrayishRep arrWordsHdrSize d p a
799 returnBc ((code,AddrRep):rest)
801 -- Default case: push taggedly, but otherwise intact.
803 -> pushAtom True d p a `thenBc` \ (code_a, sz_a) ->
804 pargs (d+sz_a) az `thenBc` \ rest ->
805 returnBc ((code_a, rep_arg) : rest)
807 -- Do magic for Ptr/Byte arrays. Push a ptr to the array on
808 -- the stack but then advance it over the headers, so as to
809 -- point to the payload.
810 parg_ArrayishRep hdrSizeW d p a
811 = pushAtom False{-irrel-} d p a `thenBc` \ (push_fo, _) ->
812 -- The ptr points at the header. Advance it over the
813 -- header and then pretend this is an Addr# (push a tag).
814 returnBc (push_fo `snocOL`
815 SWIZZLE 0 (hdrSizeW * untaggedSizeW PtrRep
818 PUSH_TAG addr_usizeW)
821 pargs d0 args_r_to_l `thenBc` \ code_n_reps ->
823 (pushs_arg, a_reps_pushed_r_to_l) = unzip code_n_reps
825 push_args = concatOL pushs_arg
826 d_after_args = d0 + sum (map taggedSizeW a_reps_pushed_r_to_l)
828 | null a_reps_pushed_r_to_l || head a_reps_pushed_r_to_l /= VoidRep
829 = panic "ByteCodeGen.generateCCall: missing or invalid World token?"
831 = reverse (tail a_reps_pushed_r_to_l)
833 -- Now: a_reps_pushed_RAW are the reps which are actually on the stack.
834 -- push_args is the code to do that.
835 -- d_after_args is the stack depth once the args are on.
837 -- Get the result rep.
838 (returns_void, r_rep)
839 = case maybe_getCCallReturnRep (idType fn) of
840 Nothing -> (True, VoidRep)
841 Just rr -> (False, rr)
843 Because the Haskell stack grows down, the a_reps refer to
844 lowest to highest addresses in that order. The args for the call
845 are on the stack. Now push an unboxed, tagged Addr# indicating
846 the C function to call. Then push a dummy placeholder for the
847 result. Finally, emit a CCALL insn with an offset pointing to the
848 Addr# just pushed, and a literal field holding the mallocville
849 address of the piece of marshalling code we generate.
850 So, just prior to the CCALL insn, the stack looks like this
851 (growing down, as usual):
856 Addr# address_of_C_fn
857 <placeholder-for-result#> (must be an unboxed type)
859 The interpreter then calls the marshall code mentioned
860 in the CCALL insn, passing it (& <placeholder-for-result#>),
861 that is, the addr of the topmost word in the stack.
862 When this returns, the placeholder will have been
863 filled in. The placeholder is slid down to the sequel
864 depth, and we RETURN.
866 This arrangement makes it simple to do f-i-dynamic since the Addr#
867 value is the first arg anyway. It also has the virtue that the
868 stack is GC-understandable at all times.
870 The marshalling code is generated specifically for this
871 call site, and so knows exactly the (Haskell) stack
872 offsets of the args, fn address and placeholder. It
873 copies the args to the C stack, calls the stacked addr,
874 and parks the result back in the placeholder. The interpreter
875 calls it as a normal C call, assuming it has a signature
876 void marshall_code ( StgWord* ptr_to_top_of_stack )
878 -- resolve static address
882 -> returnBc (False, panic "ByteCodeGen.generateCCall(dyn)")
884 -> let sym_to_find = _UNPK_ target in
885 ioToBc (lookupSymbol sym_to_find) `thenBc` \res ->
887 Just aa -> returnBc (True, aa)
888 Nothing -> ioToBc (linkFail "ByteCodeGen.generateCCall"
891 -> pprPanic "ByteCodeGen.generateCCall: casm" (ppr ccall_spec)
893 get_target_info `thenBc` \ (is_static, static_target_addr) ->
896 -- Get the arg reps, zapping the leading Addr# in the dynamic case
897 a_reps -- | trace (showSDoc (ppr a_reps_pushed_RAW)) False = error "???"
898 | is_static = a_reps_pushed_RAW
899 | otherwise = if null a_reps_pushed_RAW
900 then panic "ByteCodeGen.generateCCall: dyn with no args"
901 else tail a_reps_pushed_RAW
904 (push_Addr, d_after_Addr)
906 = (toOL [PUSH_UBX (Right static_target_addr) addr_usizeW,
907 PUSH_TAG addr_usizeW],
908 d_after_args + addr_tsizeW)
909 | otherwise -- is already on the stack
910 = (nilOL, d_after_args)
912 -- Push the return placeholder. For a call returning nothing,
913 -- this is a VoidRep (tag).
914 r_usizeW = untaggedSizeW r_rep
915 r_tsizeW = taggedSizeW r_rep
916 d_after_r = d_after_Addr + r_tsizeW
917 r_lit = mkDummyLiteral r_rep
918 push_r = (if returns_void
920 else unitOL (PUSH_UBX (Left r_lit) r_usizeW))
922 unitOL (PUSH_TAG r_usizeW)
924 -- generate the marshalling code we're going to call
927 arg1_offW = r_tsizeW + addr_tsizeW
928 args_offW = map (arg1_offW +)
929 (init (scanl (+) 0 (map taggedSizeW a_reps)))
931 ioToBc (mkMarshalCode cconv
932 (r_offW, r_rep) addr_offW
933 (zip args_offW a_reps)) `thenBc` \ addr_of_marshaller ->
934 recordMallocBc addr_of_marshaller `thenBc_`
937 do_call = unitOL (CCALL (castPtr addr_of_marshaller))
939 wrapup = mkSLIDE r_tsizeW (d_after_r - r_tsizeW - s)
940 `snocOL` RETURN r_rep
942 --trace (show (arg1_offW, args_offW , (map taggedSizeW a_reps) )) (
945 push_Addr `appOL` push_r `appOL` do_call `appOL` wrapup
950 -- Make a dummy literal, to be used as a placeholder for FFI return
951 -- values on the stack.
952 mkDummyLiteral :: PrimRep -> Literal
955 CharRep -> MachChar 0
957 WordRep -> MachWord 0
958 DoubleRep -> MachDouble 0
959 FloatRep -> MachFloat 0
960 AddrRep | taggedSizeW AddrRep == taggedSizeW WordRep -> MachWord 0
961 _ -> moan64 "mkDummyLiteral" (ppr pr)
965 -- PrelGHC.Char# -> PrelGHC.State# PrelGHC.RealWorld
966 -- -> (# PrelGHC.State# PrelGHC.RealWorld, PrelGHC.Int# #)
969 -- and check that an unboxed pair is returned wherein the first arg is VoidRep'd.
971 -- Alternatively, for call-targets returning nothing, convert
973 -- PrelGHC.Char# -> PrelGHC.State# PrelGHC.RealWorld
974 -- -> (# PrelGHC.State# PrelGHC.RealWorld #)
978 maybe_getCCallReturnRep :: Type -> Maybe PrimRep
979 maybe_getCCallReturnRep fn_ty
980 = let (a_tys, r_ty) = splitRepFunTys fn_ty
982 = if isSingleton r_reps then Nothing else Just (r_reps !! 1)
984 = case splitTyConApp_maybe (repType r_ty) of
985 (Just (tyc, tys)) -> (tyc, map typePrimRep tys)
987 ok = ( ( r_reps `lengthIs` 2 && VoidRep == head r_reps)
988 || r_reps == [VoidRep] )
989 && isUnboxedTupleTyCon r_tycon
990 && case maybe_r_rep_to_go of
992 Just r_rep -> r_rep /= PtrRep
993 -- if it was, it would be impossible
994 -- to create a valid return value
995 -- placeholder on the stack
996 blargh = pprPanic "maybe_getCCallReturn: can't handle:"
999 --trace (showSDoc (ppr (a_reps, r_reps))) (
1000 if ok then maybe_r_rep_to_go else blargh
1003 atomRep (AnnVar v) = typePrimRep (idType v)
1004 atomRep (AnnLit l) = literalPrimRep l
1005 atomRep (AnnNote n b) = atomRep (snd b)
1006 atomRep (AnnApp f (_, AnnType _)) = atomRep (snd f)
1007 atomRep (AnnLam x e) | isTyVar x = atomRep (snd e)
1008 atomRep other = pprPanic "atomRep" (ppr (deAnnotate (undefined,other)))
1011 -- Compile code which expects an unboxed Int on the top of stack,
1012 -- (call it i), and pushes the i'th closure in the supplied list
1013 -- as a consequence.
1014 implement_tagToId :: [Name] -> BcM BCInstrList
1015 implement_tagToId names
1016 = ASSERT(not (null names))
1017 getLabelsBc (length names) `thenBc` \ labels ->
1018 getLabelBc `thenBc` \ label_fail ->
1019 getLabelBc `thenBc` \ label_exit ->
1020 zip4 labels (tail labels ++ [label_fail])
1021 [0 ..] names `bind` \ infos ->
1022 map (mkStep label_exit) infos `bind` \ steps ->
1023 returnBc (concatOL steps
1025 toOL [LABEL label_fail, CASEFAIL, LABEL label_exit])
1027 mkStep l_exit (my_label, next_label, n, name_for_n)
1028 = toOL [LABEL my_label,
1029 TESTEQ_I n next_label,
1030 PUSH_G (Left name_for_n),
1034 -- Make code to unpack the top-of-stack constructor onto the stack,
1035 -- adding tags for the unboxed bits. Takes the PrimReps of the
1036 -- constructor's arguments. off_h and off_s are travelling offsets
1037 -- along the constructor and the stack.
1039 -- Supposing a constructor in the heap has layout
1041 -- Itbl p_1 ... p_i np_1 ... np_j
1043 -- then we add to the stack, shown growing down, the following:
1055 -- so that in the common case (ptrs only) a single UNPACK instr can
1056 -- copy all the payload of the constr onto the stack with no further ado.
1058 mkUnpackCode :: [Id] -- constr args
1059 -> Int -- depth before unpack
1060 -> BCEnv -- env before unpack
1061 -> (BCInstrList, Int, BCEnv)
1062 mkUnpackCode vars d p
1063 = --trace ("mkUnpackCode: " ++ showSDocDebug (ppr vars)
1064 -- ++ " --> " ++ show d' ++ "\n" ++ showSDocDebug (ppBCEnv p')
1066 (code_p `appOL` code_np, d', p')
1070 vreps = [(var, typePrimRep (idType var)) | var <- vars]
1072 -- ptrs and nonptrs, forward
1073 vreps_p = filter (isFollowableRep.snd) vreps
1074 vreps_np = filter (not.isFollowableRep.snd) vreps
1076 -- the order in which we will augment the environment
1077 vreps_env = reverse vreps_p ++ reverse vreps_np
1079 -- new env and depth
1080 vreps_env_tszsw = map (taggedSizeW.snd) vreps_env
1081 p' = addListToFM p (zip (map fst vreps_env)
1082 (mkStackOffsets d vreps_env_tszsw))
1083 d' = d + sum vreps_env_tszsw
1085 -- code to unpack the ptrs
1086 ptrs_szw = sum (map (untaggedSizeW.snd) vreps_p)
1087 code_p | null vreps_p = nilOL
1088 | otherwise = unitOL (UNPACK ptrs_szw)
1090 -- code to unpack the nonptrs
1091 vreps_env_uszw = sum (map (untaggedSizeW.snd) vreps_env)
1092 code_np = do_nptrs vreps_env_uszw ptrs_szw (reverse (map snd vreps_np))
1093 do_nptrs off_h off_s [] = nilOL
1094 do_nptrs off_h off_s (npr:nprs)
1095 | npr `elem` [IntRep, WordRep, FloatRep, DoubleRep,
1096 CharRep, AddrRep, StablePtrRep]
1099 = moan64 "ByteCodeGen.mkUnpackCode" (ppr npr)
1101 approved = UPK_TAG usizeW (off_h-usizeW) off_s `consOL` theRest
1102 theRest = do_nptrs (off_h-usizeW) (off_s + tsizeW) nprs
1103 usizeW = untaggedSizeW npr
1104 tsizeW = taggedSizeW npr
1107 -- Push an atom onto the stack, returning suitable code & number of
1108 -- stack words used. Pushes it either tagged or untagged, since
1109 -- pushAtom is used to set up the stack prior to copying into the
1110 -- heap for both APs (requiring tags) and constructors (which don't).
1112 -- NB this means NO GC between pushing atoms for a constructor and
1113 -- copying them into the heap. It probably also means that
1114 -- tail calls MUST be of the form atom{atom ... atom} since if the
1115 -- expression head was allowed to be arbitrary, there could be GC
1116 -- in between pushing the arg atoms and completing the head.
1117 -- (not sure; perhaps the allocate/doYouWantToGC interface means this
1118 -- isn't a problem; but only if arbitrary graph construction for the
1119 -- head doesn't leave this BCO, since GC might happen at the start of
1120 -- each BCO (we consult doYouWantToGC there).
1122 -- Blargh. JRS 001206
1124 -- NB (further) that the env p must map each variable to the highest-
1125 -- numbered stack slot for it. For example, if the stack has depth 4
1126 -- and we tagged-ly push (v :: Int#) on it, the value will be in stack[4],
1127 -- the tag in stack[5], the stack will have depth 6, and p must map v to
1128 -- 5 and not to 4. Stack locations are numbered from zero, so a depth
1129 -- 6 stack has valid words 0 .. 5.
1131 pushAtom :: Bool -> Int -> BCEnv -> AnnExpr' Id VarSet -> BcM (BCInstrList, Int)
1132 pushAtom tagged d p (AnnVar v)
1134 | idPrimRep v == VoidRep
1135 = if tagged then returnBc (unitOL (PUSH_TAG 0), 1)
1136 else panic "ByteCodeGen.pushAtom(VoidRep,untaggedly)"
1139 = pprPanic "pushAtom: shouldn't get an FCallId here" (ppr v)
1141 | Just primop <- isPrimOpId_maybe v
1142 = returnBc (unitOL (PUSH_G (Right primop)), 1)
1146 str = "\npushAtom " ++ showSDocDebug (ppr v)
1147 ++ " :: " ++ showSDocDebug (pprType (idType v))
1148 ++ ", depth = " ++ show d
1149 ++ ", tagged = " ++ show tagged ++ ", env =\n" ++
1150 showSDocDebug (ppBCEnv p)
1151 ++ " --> words: " ++ show (snd result) ++ "\n" ++
1152 showSDoc (nest 4 (vcat (map ppr (fromOL (fst result)))))
1153 ++ "\nendPushAtom " ++ showSDocDebug (ppr v)
1157 = case lookupBCEnv_maybe p v of
1158 Just d_v -> (toOL (nOfThem nwords (PUSH_L (d-d_v+sz_t-2))), nwords)
1159 Nothing -> ASSERT(sz_t == 1) (unitOL (PUSH_G (Left nm)), nwords)
1161 nm = case isDataConId_maybe v of
1163 Nothing -> getName v
1165 sz_t = taggedIdSizeW v
1166 sz_u = untaggedIdSizeW v
1167 nwords = if tagged then sz_t else sz_u
1171 pushAtom True d p (AnnLit lit)
1172 = pushAtom False d p (AnnLit lit) `thenBc` \ (ubx_code, ubx_size) ->
1173 returnBc (ubx_code `snocOL` PUSH_TAG ubx_size, 1 + ubx_size)
1175 pushAtom False d p (AnnLit lit)
1177 MachLabel fs -> code CodePtrRep
1178 MachWord w -> code WordRep
1179 MachInt i -> code IntRep
1180 MachFloat r -> code FloatRep
1181 MachDouble r -> code DoubleRep
1182 MachChar c -> code CharRep
1183 MachStr s -> pushStr s
1186 = let size_host_words = untaggedSizeW rep
1187 in returnBc (unitOL (PUSH_UBX (Left lit) size_host_words),
1191 = let getMallocvilleAddr
1193 CharStr s i -> returnBc (Ptr s)
1195 FastString _ l ba ->
1196 -- sigh, a string in the heap is no good to us.
1197 -- We need a static C pointer, since the type of
1198 -- a string literal is Addr#. So, copy the string
1199 -- into C land and introduce a memory leak
1200 -- at the same time.
1202 -- CAREFUL! Chars are 32 bits in ghc 4.09+
1203 in ioToBc (mallocBytes (n+1)) `thenBc` \ ptr ->
1204 recordMallocBc ptr `thenBc_`
1206 do memcpy ptr ba (fromIntegral n)
1207 pokeByteOff ptr n (fromIntegral (ord '\0') :: Word8)
1210 other -> panic "ByteCodeGen.pushAtom.pushStr"
1212 getMallocvilleAddr `thenBc` \ addr ->
1213 -- Get the addr on the stack, untaggedly
1214 returnBc (unitOL (PUSH_UBX (Right addr) 1), 1)
1220 pushAtom tagged d p (AnnApp f (_, AnnType _))
1221 = pushAtom tagged d p (snd f)
1223 pushAtom tagged d p (AnnNote note e)
1224 = pushAtom tagged d p (snd e)
1226 pushAtom tagged d p (AnnLam x e)
1228 = pushAtom tagged d p (snd e)
1230 pushAtom tagged d p other
1231 = pprPanic "ByteCodeGen.pushAtom"
1232 (pprCoreExpr (deAnnotate (undefined, other)))
1234 foreign import "memcpy" memcpy :: Ptr a -> ByteArray# -> CInt -> IO ()
1237 -- Given a bunch of alts code and their discrs, do the donkey work
1238 -- of making a multiway branch using a switch tree.
1239 -- What a load of hassle!
1240 mkMultiBranch :: Maybe Int -- # datacons in tycon, if alg alt
1241 -- a hint; generates better code
1242 -- Nothing is always safe
1243 -> [(Discr, BCInstrList)]
1245 mkMultiBranch maybe_ncons raw_ways
1246 = let d_way = filter (isNoDiscr.fst) raw_ways
1247 notd_ways = naturalMergeSortLe
1248 (\w1 w2 -> leAlt (fst w1) (fst w2))
1249 (filter (not.isNoDiscr.fst) raw_ways)
1251 mkTree :: [(Discr, BCInstrList)] -> Discr -> Discr -> BcM BCInstrList
1252 mkTree [] range_lo range_hi = returnBc the_default
1254 mkTree [val] range_lo range_hi
1255 | range_lo `eqAlt` range_hi
1256 = returnBc (snd val)
1258 = getLabelBc `thenBc` \ label_neq ->
1259 returnBc (mkTestEQ (fst val) label_neq
1261 `appOL` unitOL (LABEL label_neq)
1262 `appOL` the_default))
1264 mkTree vals range_lo range_hi
1265 = let n = length vals `div` 2
1266 vals_lo = take n vals
1267 vals_hi = drop n vals
1268 v_mid = fst (head vals_hi)
1270 getLabelBc `thenBc` \ label_geq ->
1271 mkTree vals_lo range_lo (dec v_mid) `thenBc` \ code_lo ->
1272 mkTree vals_hi v_mid range_hi `thenBc` \ code_hi ->
1273 returnBc (mkTestLT v_mid label_geq
1275 `appOL` unitOL (LABEL label_geq)
1279 = case d_way of [] -> unitOL CASEFAIL
1282 -- None of these will be needed if there are no non-default alts
1283 (mkTestLT, mkTestEQ, init_lo, init_hi)
1285 = panic "mkMultiBranch: awesome foursome"
1287 = case fst (head notd_ways) of {
1288 DiscrI _ -> ( \(DiscrI i) fail_label -> TESTLT_I i fail_label,
1289 \(DiscrI i) fail_label -> TESTEQ_I i fail_label,
1292 DiscrF _ -> ( \(DiscrF f) fail_label -> TESTLT_F f fail_label,
1293 \(DiscrF f) fail_label -> TESTEQ_F f fail_label,
1296 DiscrD _ -> ( \(DiscrD d) fail_label -> TESTLT_D d fail_label,
1297 \(DiscrD d) fail_label -> TESTEQ_D d fail_label,
1300 DiscrP _ -> ( \(DiscrP i) fail_label -> TESTLT_P i fail_label,
1301 \(DiscrP i) fail_label -> TESTEQ_P i fail_label,
1303 DiscrP algMaxBound )
1306 (algMinBound, algMaxBound)
1307 = case maybe_ncons of
1308 Just n -> (0, n - 1)
1309 Nothing -> (minBound, maxBound)
1311 (DiscrI i1) `eqAlt` (DiscrI i2) = i1 == i2
1312 (DiscrF f1) `eqAlt` (DiscrF f2) = f1 == f2
1313 (DiscrD d1) `eqAlt` (DiscrD d2) = d1 == d2
1314 (DiscrP i1) `eqAlt` (DiscrP i2) = i1 == i2
1315 NoDiscr `eqAlt` NoDiscr = True
1318 (DiscrI i1) `leAlt` (DiscrI i2) = i1 <= i2
1319 (DiscrF f1) `leAlt` (DiscrF f2) = f1 <= f2
1320 (DiscrD d1) `leAlt` (DiscrD d2) = d1 <= d2
1321 (DiscrP i1) `leAlt` (DiscrP i2) = i1 <= i2
1322 NoDiscr `leAlt` NoDiscr = True
1325 isNoDiscr NoDiscr = True
1328 dec (DiscrI i) = DiscrI (i-1)
1329 dec (DiscrP i) = DiscrP (i-1)
1330 dec other = other -- not really right, but if you
1331 -- do cases on floating values, you'll get what you deserve
1333 -- same snotty comment applies to the following
1335 minD, maxD :: Double
1341 mkTree notd_ways init_lo init_hi
1345 %************************************************************************
1347 \subsection{Supporting junk for the compilation schemes}
1349 %************************************************************************
1353 -- Describes case alts
1361 instance Outputable Discr where
1362 ppr (DiscrI i) = int i
1363 ppr (DiscrF f) = text (show f)
1364 ppr (DiscrD d) = text (show d)
1365 ppr (DiscrP i) = int i
1366 ppr NoDiscr = text "DEF"
1369 -- Find things in the BCEnv (the what's-on-the-stack-env)
1370 -- See comment preceding pushAtom for precise meaning of env contents
1371 --lookupBCEnv :: BCEnv -> Id -> Int
1372 --lookupBCEnv env nm
1373 -- = case lookupFM env nm of
1374 -- Nothing -> pprPanic "lookupBCEnv"
1375 -- (ppr nm $$ char ' ' $$ vcat (map ppr (fmToList env)))
1378 lookupBCEnv_maybe :: BCEnv -> Id -> Maybe Int
1379 lookupBCEnv_maybe = lookupFM
1382 taggedIdSizeW, untaggedIdSizeW :: Id -> Int
1383 taggedIdSizeW = taggedSizeW . typePrimRep . idType
1384 untaggedIdSizeW = untaggedSizeW . typePrimRep . idType
1386 unboxedTupleException :: a
1387 unboxedTupleException
1390 ("Bytecode generator can't handle unboxed tuples. Possibly due\n" ++
1391 "\tto foreign import/export decls in source. Workaround:\n" ++
1392 "\tcompile this module to a .o file, then restart session."))
1395 mkSLIDE n d = if d == 0 then nilOL else unitOL (SLIDE n d)
1400 %************************************************************************
1402 \subsection{The bytecode generator's monad}
1404 %************************************************************************
1408 = BcM_State { bcos :: [ProtoBCO Name], -- accumulates completed BCOs
1409 nextlabel :: Int, -- for generating local labels
1410 malloced :: [Ptr ()] } -- ptrs malloced for current BCO
1411 -- Should be free()d when it is GCd
1412 type BcM r = BcM_State -> IO (BcM_State, r)
1414 ioToBc :: IO a -> BcM a
1415 ioToBc io st = do x <- io
1418 runBc :: BcM_State -> BcM r -> IO (BcM_State, r)
1419 runBc st0 m = do (st1, res) <- m st0
1422 thenBc :: BcM a -> (a -> BcM b) -> BcM b
1423 thenBc expr cont st0
1424 = do (st1, q) <- expr st0
1425 (st2, r) <- cont q st1
1428 thenBc_ :: BcM a -> BcM b -> BcM b
1429 thenBc_ expr cont st0
1430 = do (st1, q) <- expr st0
1431 (st2, r) <- cont st1
1434 returnBc :: a -> BcM a
1435 returnBc result st = return (st, result)
1438 mapBc :: (a -> BcM b) -> [a] -> BcM [b]
1439 mapBc f [] = returnBc []
1441 = f x `thenBc` \ r ->
1442 mapBc f xs `thenBc` \ rs ->
1445 emitBc :: ([Ptr ()] -> ProtoBCO Name) -> BcM ()
1447 = return (st{bcos = bco (malloced st) : bcos st, malloced=[]}, ())
1451 | not (null (malloced st))
1452 = panic "ByteCodeGen.newbcoBc: missed prior emitBc?"
1456 recordMallocBc :: Ptr a -> BcM ()
1458 = return (st{malloced = castPtr a : malloced st}, ())
1460 getLabelBc :: BcM Int
1462 = return (st{nextlabel = 1 + nextlabel st}, nextlabel st)
1464 getLabelsBc :: Int -> BcM [Int]
1466 = let ctr = nextlabel st
1467 in return (st{nextlabel = ctr+n}, [ctr .. ctr+n-1])