1 /* ----------------------------------------------------------------------------
3 * (c) The GHC Team, 1998-2004
5 * Entry code for various built-in closure types.
7 * This file is written in a subset of C--, extended with various
8 * features specific to GHC. It is compiled by GHC directly. For the
9 * syntax of .cmm files, see the parser in ghc/compiler/cmm/CmmParse.y.
11 * --------------------------------------------------------------------------*/
15 /* ----------------------------------------------------------------------------
16 Support for the bytecode interpreter.
17 ------------------------------------------------------------------------- */
19 /* 9 bits of return code for constructors created by the interpreter. */
20 stg_interp_constr_entry
22 /* R1 points at the constructor */
23 jump %ENTRY_CODE(Sp(0));
26 stg_interp_constr1_entry { jump %RET_VEC(Sp(0),0); }
27 stg_interp_constr2_entry { jump %RET_VEC(Sp(0),1); }
28 stg_interp_constr3_entry { jump %RET_VEC(Sp(0),2); }
29 stg_interp_constr4_entry { jump %RET_VEC(Sp(0),3); }
30 stg_interp_constr5_entry { jump %RET_VEC(Sp(0),4); }
31 stg_interp_constr6_entry { jump %RET_VEC(Sp(0),5); }
32 stg_interp_constr7_entry { jump %RET_VEC(Sp(0),6); }
33 stg_interp_constr8_entry { jump %RET_VEC(Sp(0),7); }
35 /* Some info tables to be used when compiled code returns a value to
36 the interpreter, i.e. the interpreter pushes one of these onto the
37 stack before entering a value. What the code does is to
38 impedance-match the compiled return convention (in R1p/R1n/F1/D1 etc) to
39 the interpreter's convention (returned value is on top of stack),
40 and then cause the scheduler to enter the interpreter.
42 On entry, the stack (growing down) looks like this:
44 ptr to BCO holding return continuation
45 ptr to one of these info tables.
47 The info table code, both direct and vectored, must:
48 * push R1/F1/D1 on the stack, and its tag if necessary
49 * push the BCO (so it's now on the stack twice)
50 * Yield, ie, go to the scheduler.
52 Scheduler examines the t.o.s, discovers it is a BCO, and proceeds
53 directly to the bytecode interpreter. That pops the top element
54 (the BCO, containing the return continuation), and interprets it.
55 Net result: return continuation gets interpreted, with the
59 ptr to the info table just jumped thru
62 which is just what we want -- the "standard" return layout for the
65 Don't ask me how unboxed tuple returns are supposed to work. We
66 haven't got a good story about that yet.
69 INFO_TABLE_RET( stg_ctoi_R1p,
70 0/*size*/, 0/*bitmap*/, /* special layout! */
72 RET_LBL(stg_ctoi_R1p),
73 RET_LBL(stg_ctoi_R1p),
74 RET_LBL(stg_ctoi_R1p),
75 RET_LBL(stg_ctoi_R1p),
76 RET_LBL(stg_ctoi_R1p),
77 RET_LBL(stg_ctoi_R1p),
78 RET_LBL(stg_ctoi_R1p),
79 RET_LBL(stg_ctoi_R1p))
83 Sp(0) = stg_enter_info;
84 jump stg_yield_to_interpreter;
87 #if MAX_VECTORED_RTN != 8
88 #error MAX_VECTORED_RTN has changed: please modify stg_ctoi_R1p too.
92 * When the returned value is a pointer, but unlifted, in R1 ...
94 INFO_TABLE_RET( stg_ctoi_R1unpt,
95 0/*size*/, 0/*bitmap*/, /* special layout! */
100 Sp(0) = stg_gc_unpt_r1_info;
101 jump stg_yield_to_interpreter;
105 * When the returned value is a non-pointer in R1 ...
107 INFO_TABLE_RET( stg_ctoi_R1n,
108 0/*size*/, 0/*bitmap*/, /* special layout! */
113 Sp(0) = stg_gc_unbx_r1_info;
114 jump stg_yield_to_interpreter;
118 * When the returned value is in F1
120 INFO_TABLE_RET( stg_ctoi_F1,
121 0/*size*/, 0/*bitmap*/, /* special layout! */
125 F_[Sp + WDS(1)] = F1;
126 Sp(0) = stg_gc_f1_info;
127 jump stg_yield_to_interpreter;
131 * When the returned value is in D1
133 INFO_TABLE_RET( stg_ctoi_D1,
134 0/*size*/, 0/*bitmap*/, /* special layout! */
137 Sp_adj(-1) - SIZEOF_DOUBLE;
138 D_[Sp + WDS(1)] = D1;
139 Sp(0) = stg_gc_d1_info;
140 jump stg_yield_to_interpreter;
144 * When the returned value is in L1
146 INFO_TABLE_RET( stg_ctoi_L1,
147 0/*size*/, 0/*bitmap*/, /* special layout! */
151 L_[Sp + WDS(1)] = L1;
152 Sp(0) = stg_gc_l1_info;
153 jump stg_yield_to_interpreter;
157 * When the returned value is a void
159 INFO_TABLE_RET( stg_ctoi_V,
160 0/*size*/, 0/*bitmap*/, /* special layout! */
164 Sp(0) = stg_gc_void_info;
165 jump stg_yield_to_interpreter;
169 * Dummy info table pushed on the top of the stack when the interpreter
170 * should apply the BCO on the stack to its arguments, also on the
173 INFO_TABLE_RET( stg_apply_interp,
174 0/*size*/, 0/*bitmap*/, /* special layout! */
177 /* Just in case we end up in here... (we shouldn't) */
178 jump stg_yield_to_interpreter;
181 /* ----------------------------------------------------------------------------
183 ------------------------------------------------------------------------- */
185 INFO_TABLE_FUN( stg_BCO, 4, 0, BCO, "BCO", "BCO", ARG_BCO )
187 /* entering a BCO means "apply it", same as a function */
190 Sp(0) = stg_apply_interp_info;
191 jump stg_yield_to_interpreter;
194 /* ----------------------------------------------------------------------------
195 Info tables for indirections.
197 SPECIALISED INDIRECTIONS: we have a specialised indirection for each
198 kind of return (direct, vectored 0-7), so that we can avoid entering
199 the object when we know what kind of return it will do. The update
200 code (Updates.hc) updates objects with the appropriate kind of
201 indirection. We only do this for young-gen indirections.
202 ------------------------------------------------------------------------- */
204 INFO_TABLE(stg_IND,1,0,IND,"IND","IND")
206 TICK_ENT_DYN_IND(); /* tick */
207 R1 = StgInd_indirectee(R1);
212 #define IND_SPEC(label,ret) \
213 INFO_TABLE(label,1,0,IND,"IND","IND") \
215 TICK_ENT_DYN_IND(); /* tick */ \
216 R1 = StgInd_indirectee(R1); \
217 TICK_ENT_VIA_NODE(); \
221 IND_SPEC(stg_IND_direct, %ENTRY_CODE(Sp(0)))
222 IND_SPEC(stg_IND_0, %RET_VEC(Sp(0),0))
223 IND_SPEC(stg_IND_1, %RET_VEC(Sp(0),1))
224 IND_SPEC(stg_IND_2, %RET_VEC(Sp(0),2))
225 IND_SPEC(stg_IND_3, %RET_VEC(Sp(0),3))
226 IND_SPEC(stg_IND_4, %RET_VEC(Sp(0),4))
227 IND_SPEC(stg_IND_5, %RET_VEC(Sp(0),5))
228 IND_SPEC(stg_IND_6, %RET_VEC(Sp(0),6))
229 IND_SPEC(stg_IND_7, %RET_VEC(Sp(0),7))
231 INFO_TABLE(stg_IND_STATIC,1,0,IND_STATIC,"IND_STATIC","IND_STATIC")
233 TICK_ENT_STATIC_IND(); /* tick */
234 R1 = StgInd_indirectee(R1);
239 INFO_TABLE(stg_IND_PERM,1,0,IND_PERM,"IND_PERM","IND_PERM")
241 /* Don't add INDs to granularity cost */
243 /* Don't: TICK_ENT_STATIC_IND(Node); for ticky-ticky; this ind is
244 here only to help profiling */
246 #if defined(TICKY_TICKY) && !defined(PROFILING)
247 /* TICKY_TICKY && !PROFILING means PERM_IND *replaces* an IND, rather than
254 /* Enter PAP cost centre */
255 ENTER_CCS_PAP_CL(R1);
257 /* For ticky-ticky, change the perm_ind to a normal ind on first
258 * entry, so the number of ent_perm_inds is the number of *thunks*
259 * entered again, not the number of subsequent entries.
261 * Since this screws up cost centres, we die if profiling and
262 * ticky_ticky are on at the same time. KSW 1999-01.
266 # error Profiling and ticky-ticky do not mix at present!
267 # endif /* PROFILING */
268 StgHeader_info(R1) = stg_IND_info;
269 #endif /* TICKY_TICKY */
271 R1 = StgInd_indirectee(R1);
273 #if defined(TICKY_TICKY) && !defined(PROFILING)
281 INFO_TABLE(stg_IND_OLDGEN,1,0,IND_OLDGEN,"IND_OLDGEN","IND_OLDGEN")
283 TICK_ENT_STATIC_IND(); /* tick */
284 R1 = StgInd_indirectee(R1);
289 INFO_TABLE(stg_IND_OLDGEN_PERM,1,0,IND_OLDGEN_PERM,"IND_OLDGEN_PERM","IND_OLDGEN_PERM")
291 /* Don't: TICK_ENT_STATIC_IND(Node); for ticky-ticky;
292 this ind is here only to help profiling */
294 #if defined(TICKY_TICKY) && !defined(PROFILING)
295 /* TICKY_TICKY && !PROFILING means PERM_IND *replaces* an IND,
296 rather than being extra */
297 TICK_ENT_PERM_IND(R1); /* tick */
302 /* Enter PAP cost centre -- lexical scoping only */
303 ENTER_CCS_PAP_CL(R1);
305 /* see comment in IND_PERM */
308 # error Profiling and ticky-ticky do not mix at present!
309 # endif /* PROFILING */
310 StgHeader_info(R1) = stg_IND_OLDGEN_info;
311 #endif /* TICKY_TICKY */
313 R1 = StgInd_indirectee(R1);
319 /* ----------------------------------------------------------------------------
322 Entering a black hole normally causes a cyclic data dependency, but
323 in the concurrent world, black holes are synchronization points,
324 and they are turned into blocking queues when there are threads
325 waiting for the evaluation of the closure to finish.
326 ------------------------------------------------------------------------- */
328 /* Note: a BLACKHOLE must be big enough to be
329 * overwritten with an indirection/evacuee/catch. Thus we claim it
330 * has 1 non-pointer word of payload.
332 INFO_TABLE(stg_BLACKHOLE,0,1,BLACKHOLE,"BLACKHOLE","BLACKHOLE")
335 /* Before overwriting TSO_LINK */
336 STGCALL3(GranSimBlock,CurrentTSO,CurrentProc,(StgClosure *)R1 /*Node*/);
341 /* Actually this is not necessary because R1 is about to be destroyed. */
344 /* Put ourselves on the blackhole queue */
345 StgTSO_link(CurrentTSO) = W_[blackhole_queue];
346 W_[blackhole_queue] = CurrentTSO;
348 /* jot down why and on what closure we are blocked */
349 StgTSO_why_blocked(CurrentTSO) = BlockedOnBlackHole::I16;
350 StgTSO_block_info(CurrentTSO) = R1;
352 /* stg_gen_block is too heavyweight, use a specialised one */
356 #if defined(PAR) || defined(GRAN)
358 INFO_TABLE(stg_RBH,1,1,RBH,"RBH","RBH")
361 /* mainly statistics gathering for GranSim simulation */
362 STGCALL3(GranSimBlock,CurrentTSO,CurrentProc,(StgClosure *)R1 /*Node*/);
365 /* exactly the same as a BLACKHOLE_BQ_entry -- HWL */
366 /* Put ourselves on the blocking queue for this black hole */
367 TSO_link(CurrentTSO) = StgBlockingQueue_blocking_queue(R1);
368 StgBlockingQueue_blocking_queue(R1) = CurrentTSO;
369 /* jot down why and on what closure we are blocked */
370 TSO_why_blocked(CurrentTSO) = BlockedOnBlackHole::I16;
371 TSO_block_info(CurrentTSO) = R1;
373 /* PAR: dumping of event now done in blockThread -- HWL */
375 /* stg_gen_block is too heavyweight, use a specialised one */
379 INFO_TABLE(stg_RBH_Save_0,0,2,CONSTR,"RBH_Save_0","RBH_Save_0")
380 { foreign "C" barf("RBH_Save_0 object entered!"); }
382 INFO_TABLE(stg_RBH_Save_1,1,1,CONSTR,"RBH_Save_1","RBH_Save_1");
383 { foreign "C" barf("RBH_Save_1 object entered!"); }
385 INFO_TABLE(stg_RBH_Save_2,2,0,CONSTR,"RBH_Save_2","RBH_Save_2");
386 { foreign "C" barf("RBH_Save_2 object entered!"); }
388 #endif /* defined(PAR) || defined(GRAN) */
390 /* identical to BLACKHOLEs except for the infotag */
391 INFO_TABLE(stg_CAF_BLACKHOLE,0,1,CAF_BLACKHOLE,"CAF_BLACKHOLE","CAF_BLACKHOLE")
394 /* mainly statistics gathering for GranSim simulation */
395 STGCALL3(GranSimBlock,CurrentTSO,CurrentProc,(StgClosure *)R1 /*Node*/);
401 /* Put ourselves on the blackhole queue */
402 StgTSO_link(CurrentTSO) = W_[blackhole_queue];
403 W_[blackhole_queue] = CurrentTSO;
405 /* jot down why and on what closure we are blocked */
406 StgTSO_why_blocked(CurrentTSO) = BlockedOnBlackHole::I16;
407 StgTSO_block_info(CurrentTSO) = R1;
409 /* stg_gen_block is too heavyweight, use a specialised one */
413 #ifdef EAGER_BLACKHOLING
414 INFO_TABLE(stg_SE_BLACKHOLE,0,1,SE_BLACKHOLE,"SE_BLACKHOLE","SE_BLACKHOLE")
415 { foreign "C" barf("SE_BLACKHOLE object entered!"); }
417 INFO_TABLE(stg_SE_CAF_BLACKHOLE,0,1,SE_CAF_BLACKHOLE,"SE_CAF_BLACKHOLE","SE_CAF_BLACKHOLE")
418 { foreign "C" barf("SE_CAF_BLACKHOLE object entered!"); }
421 /* ----------------------------------------------------------------------------
422 ------------------------------------------------------------------------- */
424 INFO_TABLE(stg_WHITEHOLE, 0,0, INVALID_OBJECT, "WHITEHOLE", "WHITEHOLE")
425 { foreign "C" barf("WHITEHOLE object entered!"); }
427 /* ----------------------------------------------------------------------------
428 Some static info tables for things that don't get entered, and
429 therefore don't need entry code (i.e. boxed but unpointed objects)
430 NON_ENTERABLE_ENTRY_CODE now defined at the beginning of the file
431 ------------------------------------------------------------------------- */
433 INFO_TABLE(stg_TSO, 0,0,TSO, "TSO", "TSO")
434 { foreign "C" barf("TSO object entered!"); }
436 /* ----------------------------------------------------------------------------
437 Evacuees are left behind by the garbage collector. Any attempt to enter
439 ------------------------------------------------------------------------- */
441 INFO_TABLE(stg_EVACUATED,1,0,EVACUATED,"EVACUATED","EVACUATED")
442 { foreign "C" barf("EVACUATED object entered!"); }
444 /* ----------------------------------------------------------------------------
447 Live weak pointers have a special closure type. Dead ones are just
448 nullary constructors (although they live on the heap - we overwrite
449 live weak pointers with dead ones).
450 ------------------------------------------------------------------------- */
452 INFO_TABLE(stg_WEAK,0,4,WEAK,"WEAK","WEAK")
453 { foreign "C" barf("WEAK object entered!"); }
456 * It's important when turning an existing WEAK into a DEAD_WEAK
457 * (which is what finalizeWeak# does) that we don't lose the link
458 * field and break the linked list of weak pointers. Hence, we give
459 * DEAD_WEAK 4 non-pointer fields, the same as WEAK.
461 INFO_TABLE_CONSTR(stg_DEAD_WEAK,0,4,0,CONSTR,"DEAD_WEAK","DEAD_WEAK")
462 { foreign "C" barf("DEAD_WEAK object entered!"); }
464 /* ----------------------------------------------------------------------------
467 This is a static nullary constructor (like []) that we use to mark an empty
468 finalizer in a weak pointer object.
469 ------------------------------------------------------------------------- */
471 INFO_TABLE_CONSTR(stg_NO_FINALIZER,0,0,0,CONSTR_NOCAF_STATIC,"NO_FINALIZER","NO_FINALIZER")
472 { foreign "C" barf("NO_FINALIZER object entered!"); }
474 CLOSURE(stg_NO_FINALIZER_closure,stg_NO_FINALIZER);
476 /* ----------------------------------------------------------------------------
477 Stable Names are unlifted too.
478 ------------------------------------------------------------------------- */
480 INFO_TABLE(stg_STABLE_NAME,0,1,STABLE_NAME,"STABLE_NAME","STABLE_NAME")
481 { foreign "C" barf("STABLE_NAME object entered!"); }
483 /* ----------------------------------------------------------------------------
486 There are two kinds of these: full and empty. We need an info table
487 and entry code for each type.
488 ------------------------------------------------------------------------- */
490 INFO_TABLE(stg_FULL_MVAR,3,0,MVAR,"MVAR","MVAR")
491 { foreign "C" barf("FULL_MVAR object entered!"); }
493 INFO_TABLE(stg_EMPTY_MVAR,3,0,MVAR,"MVAR","MVAR")
494 { foreign "C" barf("EMPTY_MVAR object entered!"); }
496 /* -----------------------------------------------------------------------------
498 -------------------------------------------------------------------------- */
500 INFO_TABLE(stg_TVAR, 0, 0, TVAR, "TVAR", "TVAR")
501 { foreign "C" barf("TVAR object entered!"); }
503 INFO_TABLE(stg_TVAR_WAIT_QUEUE, 0, 0, TVAR_WAIT_QUEUE, "TVAR_WAIT_QUEUE", "TVAR_WAIT_QUEUE")
504 { foreign "C" barf("TVAR_WAIT_QUEUE object entered!"); }
506 INFO_TABLE(stg_TREC_CHUNK, 0, 0, TREC_CHUNK, "TREC_CHUNK", "TREC_CHUNK")
507 { foreign "C" barf("TREC_CHUNK object entered!"); }
509 INFO_TABLE(stg_TREC_HEADER, 0, 0, TREC_HEADER, "TREC_HEADER", "TREC_HEADER")
510 { foreign "C" barf("TREC_HEADER object entered!"); }
512 INFO_TABLE_CONSTR(stg_END_STM_WAIT_QUEUE,0,0,0,CONSTR_NOCAF_STATIC,"END_STM_WAIT_QUEUE","END_STM_WAIT_QUEUE")
513 { foreign "C" barf("END_STM_WAIT_QUEUE object entered!"); }
515 INFO_TABLE_CONSTR(stg_END_STM_CHUNK_LIST,0,0,0,CONSTR_NOCAF_STATIC,"END_STM_CHUNK_LIST","END_STM_CHUNK_LIST")
516 { foreign "C" barf("END_STM_CHUNK_LIST object entered!"); }
518 INFO_TABLE_CONSTR(stg_NO_TREC,0,0,0,CONSTR_NOCAF_STATIC,"NO_TREC","NO_TREC")
519 { foreign "C" barf("NO_TREC object entered!"); }
521 CLOSURE(stg_END_STM_WAIT_QUEUE_closure,stg_END_STM_WAIT_QUEUE);
523 CLOSURE(stg_END_STM_CHUNK_LIST_closure,stg_END_STM_CHUNK_LIST);
525 CLOSURE(stg_NO_TREC_closure,stg_NO_TREC);
527 /* ----------------------------------------------------------------------------
530 This is a static nullary constructor (like []) that we use to mark the
531 end of a linked TSO queue.
532 ------------------------------------------------------------------------- */
534 INFO_TABLE_CONSTR(stg_END_TSO_QUEUE,0,0,0,CONSTR_NOCAF_STATIC,"END_TSO_QUEUE","END_TSO_QUEUE")
535 { foreign "C" barf("END_TSO_QUEUE object entered!"); }
537 CLOSURE(stg_END_TSO_QUEUE_closure,stg_END_TSO_QUEUE);
539 /* ----------------------------------------------------------------------------
541 ------------------------------------------------------------------------- */
543 INFO_TABLE_CONSTR(stg_END_EXCEPTION_LIST,0,0,0,CONSTR_NOCAF_STATIC,"END_EXCEPTION_LIST","END_EXCEPTION_LIST")
544 { foreign "C" barf("END_EXCEPTION_LIST object entered!"); }
546 CLOSURE(stg_END_EXCEPTION_LIST_closure,stg_END_EXCEPTION_LIST);
548 INFO_TABLE(stg_EXCEPTION_CONS,1,1,CONSTR,"EXCEPTION_CONS","EXCEPTION_CONS")
549 { foreign "C" barf("EXCEPTION_CONS object entered!"); }
551 /* ----------------------------------------------------------------------------
554 These come in two basic flavours: arrays of data (StgArrWords) and arrays of
555 pointers (StgArrPtrs). They all have a similar layout:
557 ___________________________
558 | Info | No. of | data....
560 ---------------------------
562 These are *unpointed* objects: i.e. they cannot be entered.
564 ------------------------------------------------------------------------- */
566 INFO_TABLE(stg_ARR_WORDS, 0, 0, ARR_WORDS, "ARR_WORDS", "ARR_WORDS")
567 { foreign "C" barf("ARR_WORDS object entered!"); }
569 INFO_TABLE(stg_MUT_ARR_PTRS, 0, 0, MUT_ARR_PTRS, "MUT_ARR_PTRS", "MUT_ARR_PTRS")
570 { foreign "C" barf("MUT_ARR_PTRS object entered!"); }
572 INFO_TABLE(stg_MUT_ARR_PTRS_FROZEN, 0, 0, MUT_ARR_PTRS_FROZEN, "MUT_ARR_PTRS_FROZEN", "MUT_ARR_PTRS_FROZEN")
573 { foreign "C" barf("MUT_ARR_PTRS_FROZEN object entered!"); }
575 INFO_TABLE(stg_MUT_ARR_PTRS_FROZEN0, 0, 0, MUT_ARR_PTRS_FROZEN0, "MUT_ARR_PTRS_FROZEN0", "MUT_ARR_PTRS_FROZEN0")
576 { foreign "C" barf("MUT_ARR_PTRS_FROZEN0 object entered!"); }
578 /* ----------------------------------------------------------------------------
580 ------------------------------------------------------------------------- */
582 INFO_TABLE(stg_MUT_VAR, 1, 0, MUT_VAR, "MUT_VAR", "MUT_VAR")
583 { foreign "C" barf("MUT_VAR object entered!"); }
585 /* ----------------------------------------------------------------------------
588 Entering this closure will just return to the address on the top of the
589 stack. Useful for getting a thread in a canonical form where we can
590 just enter the top stack word to start the thread. (see deleteThread)
591 * ------------------------------------------------------------------------- */
593 INFO_TABLE( stg_dummy_ret, 0, 0, CONSTR_NOCAF_STATIC, "DUMMY_RET", "DUMMY_RET")
595 jump %ENTRY_CODE(Sp(0));
597 CLOSURE(stg_dummy_ret_closure,stg_dummy_ret);
599 /* ----------------------------------------------------------------------------
600 CHARLIKE and INTLIKE closures.
602 These are static representations of Chars and small Ints, so that
603 we can remove dynamic Chars and Ints during garbage collection and
604 replace them with references to the static objects.
605 ------------------------------------------------------------------------- */
607 #if defined(ENABLE_WIN32_DLL_SUPPORT)
609 * When sticking the RTS in a DLL, we delay populating the
610 * Charlike and Intlike tables until load-time, which is only
611 * when we've got the real addresses to the C# and I# closures.
614 static INFO_TBL_CONST StgInfoTable czh_static_info;
615 static INFO_TBL_CONST StgInfoTable izh_static_info;
616 #define Char_hash_static_info czh_static_info
617 #define Int_hash_static_info izh_static_info
619 #define Char_hash_static_info GHCziBase_Czh_static
620 #define Int_hash_static_info GHCziBase_Izh_static
624 #define CHARLIKE_HDR(n) CLOSURE(Char_hash_static_info, n)
625 #define INTLIKE_HDR(n) CLOSURE(Int_hash_static_info, n)
627 /* put these in the *data* section, since the garbage collector relies
628 * on the fact that static closures live in the data section.
631 /* end the name with _closure, to convince the mangler this is a closure */
634 stg_CHARLIKE_closure:
895 INTLIKE_HDR(-16) /* MIN_INTLIKE == -16 */
927 INTLIKE_HDR(16) /* MAX_INTLIKE == 16 */