2 % (c) The AQUA Project, Glasgow University, 1993-1998
6 module StixPrim ( primCode, amodeToStix, amodeToStix' ) where
8 #include "HsVersions.h"
14 import AbsCSyn hiding ( spRel )
15 import AbsCUtils ( getAmodeRep, mixedTypeLocn )
16 import SMRep ( fixedHdrSize )
17 import Literal ( Literal(..), word2IntLit )
18 import PrimOp ( PrimOp(..), CCall(..), CCallTarget(..) )
19 import PrimRep ( PrimRep(..) )
20 import UniqSupply ( returnUs, thenUs, getUniqueUs, UniqSM )
21 import Constants ( mIN_INTLIKE, mIN_CHARLIKE, uF_UPDATEE, bLOCK_SIZE,
22 rESERVED_STACK_WORDS )
23 import CLabel ( mkIntlikeClosureLabel, mkCharlikeClosureLabel,
24 mkMAP_FROZEN_infoLabel, mkForeignLabel )
25 import CallConv ( cCallConv )
32 The main honcho here is primCode, which handles the guts of COpStmts.
36 :: [CAddrMode] -- results
38 -> [CAddrMode] -- args
39 -> UniqSM StixTreeList
42 First, the dreaded @ccall@. We can't handle @casm@s.
44 Usually, this compiles to an assignment, but when the left-hand side
45 is empty, we just perform the call and ignore the result.
47 btw Why not let programmer use casm to provide assembly code instead
50 The (MP) integer operations are a true nightmare. Since we don't have
51 a convenient abstract way of allocating temporary variables on the (C)
52 stack, we use the space just below HpLim for the @MP_INT@ structures,
53 and modify our heap check accordingly.
56 -- NB: ordering of clauses somewhere driven by
57 -- the desire to getting sane patt-matching behavior
59 primCode [res] IntegerCmpOp args@[sa1,da1, sa2,da2]
60 = gmpCompare res (sa1,da1, sa2,da2)
62 primCode [res] IntegerCmpIntOp args@[sa1,da1,ai]
63 = gmpCompareInt res (sa1,da1,ai)
65 primCode [res] Integer2IntOp arg@[sa,da]
66 = gmpInteger2Int res (sa,da)
68 primCode [res] Integer2WordOp arg@[sa,da]
69 = gmpInteger2Word res (sa,da)
71 primCode [res] Int2AddrOp [arg]
72 = simpleCoercion AddrRep res arg
74 primCode [res] Addr2IntOp [arg]
75 = simpleCoercion IntRep res arg
77 primCode [res] Int2WordOp [arg]
78 = simpleCoercion IntRep{-WordRep?-} res arg
80 primCode [res] Word2IntOp [arg]
81 = simpleCoercion IntRep res arg
83 primCode [res] AddrToHValueOp [arg]
84 = simpleCoercion PtrRep res arg
88 primCode [res] SameMutableArrayOp args
90 compare = StPrim AddrEqOp (map amodeToStix args)
91 assign = StAssign IntRep (amodeToStix res) compare
93 returnUs (\xs -> assign : xs)
95 primCode res@[_] SameMutableByteArrayOp args
96 = primCode res SameMutableArrayOp args
98 primCode res@[_] SameMutVarOp args
99 = primCode res SameMutableArrayOp args
101 primCode res@[_] SameMVarOp args
102 = primCode res SameMutableArrayOp args
105 Freezing an array of pointers is a double assignment. We fix the
106 header of the ``new'' closure because the lhs is probably a better
107 addressing mode for the indirection (most likely, it's a VanillaReg).
111 primCode [lhs] UnsafeFreezeArrayOp [rhs]
113 lhs' = amodeToStix lhs
114 rhs' = amodeToStix rhs
115 header = StInd PtrRep lhs'
116 assign = StAssign PtrRep lhs' rhs'
117 freeze = StAssign PtrRep header mutArrPtrsFrozen_info
119 returnUs (\xs -> assign : freeze : xs)
121 primCode [lhs] UnsafeFreezeByteArrayOp [rhs]
122 = simpleCoercion PtrRep lhs rhs
125 Returning the size of (mutable) byte arrays is just
126 an indexing operation.
129 primCode [lhs] SizeofByteArrayOp [rhs]
131 lhs' = amodeToStix lhs
132 rhs' = amodeToStix rhs
133 sz = StIndex IntRep rhs' fixedHS
134 assign = StAssign IntRep lhs' (StInd IntRep sz)
136 returnUs (\xs -> assign : xs)
138 primCode [lhs] SizeofMutableByteArrayOp [rhs]
140 lhs' = amodeToStix lhs
141 rhs' = amodeToStix rhs
142 sz = StIndex IntRep rhs' fixedHS
143 assign = StAssign IntRep lhs' (StInd IntRep sz)
145 returnUs (\xs -> assign : xs)
149 Most other array primitives translate to simple indexing.
152 primCode lhs@[_] IndexArrayOp args
153 = primCode lhs ReadArrayOp args
155 primCode [lhs] ReadArrayOp [obj, ix]
157 lhs' = amodeToStix lhs
158 obj' = amodeToStix obj
160 base = StIndex IntRep obj' arrPtrsHS
161 assign = StAssign PtrRep lhs' (StInd PtrRep (StIndex PtrRep base ix'))
163 returnUs (\xs -> assign : xs)
165 primCode [] WriteArrayOp [obj, ix, v]
167 obj' = amodeToStix obj
170 base = StIndex IntRep obj' arrPtrsHS
171 assign = StAssign PtrRep (StInd PtrRep (StIndex PtrRep base ix')) v'
173 returnUs (\xs -> assign : xs)
175 primCode [] WriteForeignObjOp [obj, v]
177 obj' = amodeToStix obj
179 obj'' = StIndex AddrRep obj' (StInt 4711) -- fixedHS
180 assign = StAssign AddrRep (StInd AddrRep obj'') v'
182 returnUs (\xs -> assign : xs)
184 -- NB: indexing in "pk" units, *not* in bytes (WDP 95/09)
185 primCode ls IndexByteArrayOp_Char rs = primCode_ReadByteArrayOp Word8Rep ls rs
186 primCode ls IndexByteArrayOp_Int rs = primCode_ReadByteArrayOp IntRep ls rs
187 primCode ls IndexByteArrayOp_Word rs = primCode_ReadByteArrayOp WordRep ls rs
188 primCode ls IndexByteArrayOp_Addr rs = primCode_ReadByteArrayOp AddrRep ls rs
189 primCode ls IndexByteArrayOp_Float rs = primCode_ReadByteArrayOp FloatRep ls rs
190 primCode ls IndexByteArrayOp_Double rs = primCode_ReadByteArrayOp DoubleRep ls rs
191 primCode ls IndexByteArrayOp_StablePtr rs = primCode_ReadByteArrayOp StablePtrRep ls rs
192 primCode ls IndexByteArrayOp_Int64 rs = primCode_ReadByteArrayOp Int64Rep ls rs
193 primCode ls IndexByteArrayOp_Word64 rs = primCode_ReadByteArrayOp Word64Rep ls rs
195 primCode ls ReadByteArrayOp_Char rs = primCode_ReadByteArrayOp Word8Rep ls rs
196 primCode ls ReadByteArrayOp_Int rs = primCode_ReadByteArrayOp IntRep ls rs
197 primCode ls ReadByteArrayOp_Word rs = primCode_ReadByteArrayOp WordRep ls rs
198 primCode ls ReadByteArrayOp_Addr rs = primCode_ReadByteArrayOp AddrRep ls rs
199 primCode ls ReadByteArrayOp_Float rs = primCode_ReadByteArrayOp FloatRep ls rs
200 primCode ls ReadByteArrayOp_Double rs = primCode_ReadByteArrayOp DoubleRep ls rs
201 primCode ls ReadByteArrayOp_StablePtr rs = primCode_ReadByteArrayOp StablePtrRep ls rs
202 primCode ls ReadByteArrayOp_Int64 rs = primCode_ReadByteArrayOp Int64Rep ls rs
203 primCode ls ReadByteArrayOp_Word64 rs = primCode_ReadByteArrayOp Word64Rep ls rs
205 primCode ls ReadOffAddrOp_Char rs = primCode_IndexOffAddrOp Word8Rep ls rs
206 primCode ls ReadOffAddrOp_Int rs = primCode_IndexOffAddrOp IntRep ls rs
207 primCode ls ReadOffAddrOp_Word rs = primCode_IndexOffAddrOp WordRep ls rs
208 primCode ls ReadOffAddrOp_Addr rs = primCode_IndexOffAddrOp AddrRep ls rs
209 primCode ls ReadOffAddrOp_Float rs = primCode_IndexOffAddrOp FloatRep ls rs
210 primCode ls ReadOffAddrOp_Double rs = primCode_IndexOffAddrOp DoubleRep ls rs
211 primCode ls ReadOffAddrOp_StablePtr rs = primCode_IndexOffAddrOp StablePtrRep ls rs
212 primCode ls ReadOffAddrOp_Int64 rs = primCode_IndexOffAddrOp Int64Rep ls rs
213 primCode ls ReadOffAddrOp_Word64 rs = primCode_IndexOffAddrOp Word64Rep ls rs
215 primCode ls IndexOffAddrOp_Char rs = primCode_IndexOffAddrOp Word8Rep ls rs
216 primCode ls IndexOffAddrOp_Int rs = primCode_IndexOffAddrOp IntRep ls rs
217 primCode ls IndexOffAddrOp_Word rs = primCode_IndexOffAddrOp WordRep ls rs
218 primCode ls IndexOffAddrOp_Addr rs = primCode_IndexOffAddrOp AddrRep ls rs
219 primCode ls IndexOffAddrOp_Float rs = primCode_IndexOffAddrOp FloatRep ls rs
220 primCode ls IndexOffAddrOp_Double rs = primCode_IndexOffAddrOp DoubleRep ls rs
221 primCode ls IndexOffAddrOp_StablePtr rs = primCode_IndexOffAddrOp StablePtrRep ls rs
222 primCode ls IndexOffAddrOp_Int64 rs = primCode_IndexOffAddrOp Int64Rep ls rs
223 primCode ls IndexOffAddrOp_Word64 rs = primCode_IndexOffAddrOp Word64Rep ls rs
225 primCode ls IndexOffForeignObjOp_Char rs = primCode_IndexOffForeignObjOp Word8Rep ls rs
226 primCode ls IndexOffForeignObjOp_Int rs = primCode_IndexOffForeignObjOp IntRep ls rs
227 primCode ls IndexOffForeignObjOp_Word rs = primCode_IndexOffForeignObjOp WordRep ls rs
228 primCode ls IndexOffForeignObjOp_Addr rs = primCode_IndexOffForeignObjOp AddrRep ls rs
229 primCode ls IndexOffForeignObjOp_Float rs = primCode_IndexOffForeignObjOp FloatRep ls rs
230 primCode ls IndexOffForeignObjOp_Double rs = primCode_IndexOffForeignObjOp DoubleRep ls rs
231 primCode ls IndexOffForeignObjOp_StablePtr rs = primCode_IndexOffForeignObjOp StablePtrRep ls rs
232 primCode ls IndexOffForeignObjOp_Int64 rs = primCode_IndexOffForeignObjOp Int64Rep ls rs
233 primCode ls IndexOffForeignObjOp_Word64 rs = primCode_IndexOffForeignObjOp Word64Rep ls rs
235 primCode ls WriteOffAddrOp_Word8 rs = primCode_WriteOffAddrOp Word8Rep ls rs
236 primCode ls WriteOffAddrOp_Char rs = primCode_WriteOffAddrOp Word8Rep ls rs
237 primCode ls WriteOffAddrOp_Int rs = primCode_WriteOffAddrOp IntRep ls rs
238 primCode ls WriteOffAddrOp_Word rs = primCode_WriteOffAddrOp WordRep ls rs
239 primCode ls WriteOffAddrOp_Addr rs = primCode_WriteOffAddrOp AddrRep ls rs
240 primCode ls WriteOffAddrOp_Float rs = primCode_WriteOffAddrOp FloatRep ls rs
241 primCode ls WriteOffAddrOp_Double rs = primCode_WriteOffAddrOp DoubleRep ls rs
242 primCode ls WriteOffAddrOp_StablePtr rs = primCode_WriteOffAddrOp StablePtrRep ls rs
243 primCode ls WriteOffAddrOp_Int64 rs = primCode_WriteOffAddrOp Int64Rep ls rs
244 primCode ls WriteOffAddrOp_Word64 rs = primCode_WriteOffAddrOp Word64Rep ls rs
246 primCode ls WriteByteArrayOp_Char rs = primCode_WriteByteArrayOp Word8Rep ls rs
247 primCode ls WriteByteArrayOp_Int rs = primCode_WriteByteArrayOp IntRep ls rs
248 primCode ls WriteByteArrayOp_Word rs = primCode_WriteByteArrayOp WordRep ls rs
249 primCode ls WriteByteArrayOp_Addr rs = primCode_WriteByteArrayOp AddrRep ls rs
250 primCode ls WriteByteArrayOp_Float rs = primCode_WriteByteArrayOp FloatRep ls rs
251 primCode ls WriteByteArrayOp_Double rs = primCode_WriteByteArrayOp DoubleRep ls rs
252 primCode ls WriteByteArrayOp_StablePtr rs = primCode_WriteByteArrayOp StablePtrRep ls rs
253 primCode ls WriteByteArrayOp_Int64 rs = primCode_WriteByteArrayOp Int64Rep ls rs
254 primCode ls WriteByteArrayOp_Word64 rs = primCode_WriteByteArrayOp Word64Rep ls rs
258 ToDo: saving/restoring of volatile regs around ccalls.
260 JRS, 001113: always do the call of suspendThread and resumeThread as a ccall
261 rather than inheriting the calling convention of the thing which we're really
265 primCode lhs (CCallOp (CCall (StaticTarget fn) is_asm may_gc cconv)) rhs
266 | is_asm = error "ERROR: Native code generator can't handle casm"
267 | not may_gc = returnUs (\xs -> ccall : xs)
269 save_thread_state `thenUs` \ save ->
270 load_thread_state `thenUs` \ load ->
271 getUniqueUs `thenUs` \ uniq ->
273 id = StReg (StixTemp uniq IntRep)
275 suspend = StAssign IntRep id
276 (StCall SLIT("suspendThread") {-no:cconv-} cCallConv
278 resume = StCall SLIT("resumeThread") {-no:cconv-} cCallConv
281 returnUs (\xs -> save (suspend : ccall : resume : load xs))
284 args = map amodeCodeForCCall rhs
285 amodeCodeForCCall x =
286 let base = amodeToStix' x
288 case getAmodeRep x of
289 ArrayRep -> StIndex PtrRep base arrPtrsHS
290 ByteArrayRep -> StIndex IntRep base arrWordsHS
291 ForeignObjRep -> StInd PtrRep (StIndex PtrRep base fixedHS)
295 [] -> StCall fn cconv VoidRep args
297 let lhs' = amodeToStix lhs
298 pk = case getAmodeRep lhs of
300 DoubleRep -> DoubleRep
303 StAssign pk lhs' (StCall fn cconv pk args)
306 DataToTagOp won't work for 64-bit archs, as it is.
309 primCode [lhs] DataToTagOp [arg]
310 = let lhs' = amodeToStix lhs
311 arg' = amodeToStix arg
312 infoptr = StInd PtrRep arg'
313 word_32 = StInd WordRep (StIndex PtrRep infoptr (StInt (-1)))
314 masked_le32 = StPrim SrlOp [word_32, StInt 16]
315 masked_be32 = StPrim AndOp [word_32, StInt 65535]
316 #ifdef WORDS_BIGENDIAN
321 assign = StAssign IntRep lhs' masked
323 returnUs (\xs -> assign : xs)
326 MutVars are pretty simple.
327 #define writeMutVarzh(a,v) (P_)(((StgMutVar *)(a))->var)=(v)
330 primCode [] WriteMutVarOp [aa,vv]
331 = let aa_s = amodeToStix aa
332 vv_s = amodeToStix vv
333 var_field = StIndex PtrRep aa_s fixedHS
334 assign = StAssign PtrRep (StInd PtrRep var_field) vv_s
336 returnUs (\xs -> assign : xs)
338 primCode [rr] ReadMutVarOp [aa]
339 = let aa_s = amodeToStix aa
340 rr_s = amodeToStix rr
341 var_field = StIndex PtrRep aa_s fixedHS
342 assign = StAssign PtrRep rr_s (StInd PtrRep var_field)
344 returnUs (\xs -> assign : xs)
350 primCode [rr] ForeignObjToAddrOp [fo]
351 = let code = StAssign AddrRep (amodeToStix rr)
353 (StIndex PtrRep (amodeToStix fo) fixedHS))
355 returnUs (\xs -> code : xs)
357 primCode [] TouchOp [_] = returnUs id
360 Now the more mundane operations.
365 lhs' = map amodeToStix lhs
366 rhs' = map amodeToStix' rhs
367 pk = getAmodeRep (head lhs)
369 returnUs (\ xs -> simplePrim pk lhs' op rhs' : xs)
372 Helper fns for some array ops.
375 primCode_ReadByteArrayOp pk [lhs] [obj, ix]
377 lhs' = amodeToStix lhs
378 obj' = amodeToStix obj
380 base = StIndex IntRep obj' arrWordsHS
381 assign = StAssign pk lhs' (StInd pk (StIndex pk base ix'))
383 returnUs (\xs -> assign : xs)
386 primCode_IndexOffAddrOp pk [lhs] [obj, ix]
388 lhs' = amodeToStix lhs
389 obj' = amodeToStix obj
391 assign = StAssign pk lhs' (StInd pk (StIndex pk obj' ix'))
393 returnUs (\xs -> assign : xs)
396 primCode_IndexOffForeignObjOp pk [lhs] [obj, ix]
398 lhs' = amodeToStix lhs
399 obj' = amodeToStix obj
401 obj'' = StIndex AddrRep obj' fixedHS
402 assign = StAssign pk lhs' (StInd pk (StIndex pk obj'' ix'))
404 returnUs (\xs -> assign : xs)
407 primCode_WriteOffAddrOp pk [] [obj, ix, v]
409 obj' = amodeToStix obj
412 assign = StAssign pk (StInd pk (StIndex pk obj' ix')) v'
414 returnUs (\xs -> assign : xs)
417 primCode_WriteByteArrayOp pk [] [obj, ix, v]
419 obj' = amodeToStix obj
422 base = StIndex IntRep obj' arrWordsHS
423 assign = StAssign pk (StInd pk (StIndex pk base ix')) v'
425 returnUs (\xs -> assign : xs)
434 -> UniqSM StixTreeList
436 simpleCoercion pk lhs rhs
437 = returnUs (\xs -> StAssign pk (amodeToStix lhs) (amodeToStix rhs) : xs)
440 Here we try to rewrite primitives into a form the code generator can
441 understand. Any primitives not handled here must be handled at the
442 level of the specific code generator.
446 :: PrimRep -- Rep of first destination
447 -> [StixTree] -- Destinations
453 Now look for something more conventional.
456 simplePrim pk [lhs] op rest = StAssign pk lhs (StPrim op rest)
457 simplePrim pk as op bs = simplePrim_error op
460 = error ("ERROR: primitive operation `"++show op++"'cannot be handled\nby the native-code generator. Workaround: use -fvia-C.\n(Perhaps you should report it as a GHC bug, also.)\n")
463 %---------------------------------------------------------------------
465 Here we generate the Stix code for CAddrModes.
467 When a character is fetched from a mixed type location, we have to do
468 an extra cast. This is reflected in amodeCode', which is for rhs
469 amodes that might possibly need the extra cast.
472 amodeToStix, amodeToStix' :: CAddrMode -> StixTree
474 amodeToStix'{-'-} am@(CVal rr CharRep)
475 | mixedTypeLocn am = StPrim ChrOp [amodeToStix am]
476 | otherwise = amodeToStix am
478 amodeToStix' am = amodeToStix am
481 amodeToStix am@(CVal rr CharRep)
483 = StInd IntRep (amodeToStix (CAddr rr))
485 amodeToStix (CVal rr pk) = StInd pk (amodeToStix (CAddr rr))
487 amodeToStix (CAddr (SpRel off))
488 = StIndex PtrRep stgSp (StInt (toInteger (iBox off)))
490 amodeToStix (CAddr (HpRel off))
491 = StIndex IntRep stgHp (StInt (toInteger (- (iBox off))))
493 amodeToStix (CAddr (NodeRel off))
494 = StIndex IntRep stgNode (StInt (toInteger (iBox off)))
496 amodeToStix (CAddr (CIndex base off pk))
497 = StIndex pk (amodeToStix base) (amodeToStix off)
499 amodeToStix (CReg magic) = StReg (StixMagicId magic)
500 amodeToStix (CTemp uniq pk) = StReg (StixTemp uniq pk)
502 amodeToStix (CLbl lbl _) = StCLbl lbl
504 -- For CharLike and IntLike, we attempt some trivial constant-folding here.
506 amodeToStix (CCharLike (CLit (MachChar c)))
507 = StIndex Word8Rep cHARLIKE_closure (StInt (toInteger off))
509 off = charLikeSize * (c - mIN_CHARLIKE)
511 amodeToStix (CCharLike x)
514 amodeToStix (CIntLike (CLit (MachInt i)))
515 = StIndex Word8Rep iNTLIKE_closure (StInt (toInteger off))
517 off = intLikeSize * (fromInteger (i - mIN_INTLIKE))
519 amodeToStix (CIntLike x)
522 amodeToStix (CLit core)
524 MachChar c -> StInt (toInteger c)
525 MachStr s -> StString s
526 MachAddr a -> StInt a
528 MachWord w -> case word2IntLit core of MachInt iw -> StInt iw
529 MachLitLit s _ -> litLitErr
530 MachLabel l -> StCLbl (mkForeignLabel l False{-ToDo: dynamic-})
531 MachFloat d -> StFloat d
532 MachDouble d -> StDouble d
533 _ -> panic "amodeToStix:core literal"
535 amodeToStix (CMacroExpr _ macro [arg])
537 ENTRY_CODE -> amodeToStix arg
538 ARG_TAG -> amodeToStix arg -- just an integer no. of words
540 #ifdef WORDS_BIGENDIAN
542 [StInd WordRep (StIndex PtrRep (amodeToStix arg)
543 (StInt (toInteger (-1)))),
547 [StInd WordRep (StIndex PtrRep (amodeToStix arg)
548 (StInt (toInteger (-1)))),
552 -> StInd PtrRep (StIndex PtrRep (amodeToStix arg)
553 (StInt (toInteger uF_UPDATEE)))
556 panic "native code generator can't compile lit-lits, use -fvia-C"
559 Sizes of the CharLike and IntLike closures that are arranged as arrays
560 in the data segment. (These are in bytes.)
563 -- The INTLIKE base pointer
565 iNTLIKE_closure :: StixTree
566 iNTLIKE_closure = StCLbl mkIntlikeClosureLabel
570 cHARLIKE_closure :: StixTree
571 cHARLIKE_closure = StCLbl mkCharlikeClosureLabel
573 mutArrPtrsFrozen_info = StCLbl mkMAP_FROZEN_infoLabel
575 -- these are the sizes of charLike and intLike closures, in _bytes_.
576 charLikeSize = (fixedHdrSize + 1) * (fromInteger (sizeOf PtrRep))
577 intLikeSize = (fixedHdrSize + 1) * (fromInteger (sizeOf PtrRep))
583 = getUniqueUs `thenUs` \tso_uq ->
584 let tso = StReg (StixTemp tso_uq ThreadIdRep) in
586 StAssign ThreadIdRep tso stgCurrentTSO :
588 (StInd PtrRep (StPrim IntAddOp
589 [tso, StInt (toInteger (TSO_SP*BYTES_PER_WORD))]))
592 (StInd PtrRep (StPrim IntAddOp
593 [tso, StInt (toInteger (TSO_SU*BYTES_PER_WORD))]))
596 (StInd PtrRep (StPrim IntAddOp
598 StInt (toInteger (BDESCR_FREE * BYTES_PER_WORD))]))
599 (StPrim IntAddOp [stgHp, StInt (toInteger (1 * BYTES_PER_WORD))]) :
604 = getUniqueUs `thenUs` \tso_uq ->
605 let tso = StReg (StixTemp tso_uq ThreadIdRep) in
607 StAssign ThreadIdRep tso stgCurrentTSO :
608 StAssign PtrRep stgSp
609 (StInd PtrRep (StPrim IntAddOp
610 [tso, StInt (toInteger (TSO_SP*BYTES_PER_WORD))])) :
611 StAssign PtrRep stgSu
612 (StInd PtrRep (StPrim IntAddOp
613 [tso, StInt (toInteger (TSO_SU*BYTES_PER_WORD))])) :
614 StAssign PtrRep stgSpLim
615 (StPrim IntAddOp [tso,
616 StInt (toInteger ((TSO_STACK + rESERVED_STACK_WORDS)
617 *BYTES_PER_WORD))]) :
618 StAssign PtrRep stgHp
620 StInd PtrRep (StPrim IntAddOp
622 StInt (toInteger (BDESCR_FREE * BYTES_PER_WORD))]),
623 StInt (toInteger (1 * BYTES_PER_WORD))
625 StAssign PtrRep stgHpLim
627 StInd PtrRep (StPrim IntAddOp
629 StInt (toInteger (BDESCR_START * BYTES_PER_WORD))]),
630 StInt (toInteger (bLOCK_SIZE - (1 * BYTES_PER_WORD)))