1 /* -----------------------------------------------------------------------------
3 * (c) The GHC Team, 1998-2004
5 * Registers in the STG machine.
7 * The STG machine has a collection of "registers", each one of which
8 * may or may not correspond to an actual machine register when
11 * The register set is backed by a table in memory (struct
12 * StgRegTable). If a particular STG register is not mapped to a
13 * machine register, then the apprpriate slot in this table is used
16 * This table is itself pointed to by another register, BaseReg. If
17 * BaseReg is not in a machine register, then the register table is
18 * used from an absolute location (MainCapability).
20 * ---------------------------------------------------------------------------*/
27 * This is the table that holds shadow-locations for all the STG
28 * registers. The shadow locations are used when:
30 * 1) the particular register isn't mapped to a real machine
31 * register, probably because there's a shortage of real registers.
32 * 2) caller-saves registers are saved across a CCall
35 typedef struct StgSparkPool_ {
43 StgFunPtr stgGCEnter1;
48 * Vanilla registers are given this union type, which is purely so
49 * that we can cast the vanilla reg to a variety of types with the
50 * minimum of syntax. eg. R1.w instead of (StgWord)R1.
61 StgStackOffset offset; /* unused? */
66 typedef struct StgRegTable_ {
75 StgUnion rR9; // used occasionally by heap/stack checks
76 StgUnion rR10; // used occasionally by heap/stack checks
88 struct StgTSO_ *rCurrentTSO;
89 struct bdescr_ *rNursery;
90 struct bdescr_ *rCurrentNursery;
91 StgWord rHpAlloc; // number of *bytes* being allocated in heap
92 #if defined(SMP) || defined(PAR)
93 StgSparkPool rSparks; // per-task spark pool
98 /* A capability is a combination of a FunTable and a RegTable. In STG
99 * code, BaseReg normally points to the RegTable portion of this
100 * structure, so that we can index both forwards and backwards to take
101 * advantage of shorter instruction forms on some archs (eg. x86).
103 typedef struct Capability_ {
107 struct Capability_ *link; /* per-task register tables are linked together */
111 /* No such thing as a MainCapability under SMP - each thread must have
112 * its own Capability.
116 extern W_ MainCapability[];
118 extern DLL_IMPORT_RTS Capability MainCapability;
125 * Registers Hp and HpLim are global across the entire system, and are
126 * copied into the RegTable before executing a thread.
128 * Registers Sp and SpLim are saved in the TSO for the
129 * thread, but are copied into the RegTable before executing a thread.
131 * All other registers are "general purpose", and are used for passing
132 * arguments to functions, and returning values. The code generator
133 * knows how many of these are in real registers, and avoids
134 * generating code that uses non-real registers. General purpose
135 * registers are never saved when returning to the scheduler, instead
136 * we save whatever is live at the time on the stack, and restore it
137 * later. This should reduce the context switch time, amongst other
140 * For argument passing, the stack will be used in preference to
141 * pseudo-registers if the architecture has too few general purpose
144 * Some special RTS functions like newArray and the Integer primitives
145 * expect their arguments to be in registers R1-Rn, so we use these
146 * (pseudo-)registers in those cases.
150 * Locations for saving per-thread registers.
153 #define SAVE_Sp (CurrentTSO->sp)
154 #define SAVE_SpLim (CurrentTSO->splim)
156 #define SAVE_Hp (BaseReg->rHp)
157 #define SAVE_HpLim (BaseReg->rHpLim)
159 #define SAVE_CurrentTSO (BaseReg->rCurrentTSO)
160 #define SAVE_CurrentNursery (BaseReg->rCurrentNursery)
161 #define SAVE_HpAlloc (BaseReg->rHpAlloc)
162 #define SAVE_SparkHd (BaseReg->rSparks.hd)
163 #define SAVE_SparkTl (BaseReg->rSparks.tl)
164 #define SAVE_SparkBase (BaseReg->rSparks.base)
165 #define SAVE_SparkLim (BaseReg->rSparks.lim)
167 /* We sometimes need to save registers across a C-call, eg. if they
168 * are clobbered in the standard calling convention. We define the
169 * save locations for all registers in the register table.
172 #define SAVE_R1 (BaseReg->rR1)
173 #define SAVE_R2 (BaseReg->rR2)
174 #define SAVE_R3 (BaseReg->rR3)
175 #define SAVE_R4 (BaseReg->rR4)
176 #define SAVE_R5 (BaseReg->rR5)
177 #define SAVE_R6 (BaseReg->rR6)
178 #define SAVE_R7 (BaseReg->rR7)
179 #define SAVE_R8 (BaseReg->rR8)
181 #define SAVE_F1 (BaseReg->rF1)
182 #define SAVE_F2 (BaseReg->rF2)
183 #define SAVE_F3 (BaseReg->rF3)
184 #define SAVE_F4 (BaseReg->rF4)
186 #define SAVE_D1 (BaseReg->rD1)
187 #define SAVE_D2 (BaseReg->rD2)
189 #define SAVE_L1 (BaseReg->rL1)
191 /* -----------------------------------------------------------------------------
192 * Emit the GCC-specific register declarations for each machine
193 * register being used. If any STG register isn't mapped to a machine
194 * register, then map it to an offset from BaseReg.
196 * First, the general purpose registers. The idea is, if a particular
197 * general-purpose STG register can't be mapped to a real machine
198 * register, it won't be used at all. Instead, we'll use the stack.
200 * This is an improvement on the way things used to be done, when all
201 * registers were mapped to locations in the register table, and stuff
202 * was being shifted from the stack to the register table and back
203 * again for no good reason (on register-poor architectures).
206 /* define NO_REGS to omit register declarations - used in RTS C code
207 * that needs all the STG definitions but not the global register
210 #define GLOBAL_REG_DECL(type,name,reg) register type name REG(reg);
212 #if defined(REG_R1) && !defined(NO_GLOBAL_REG_DECLS)
213 GLOBAL_REG_DECL(StgUnion,R1,REG_R1)
215 # define R1 (BaseReg->rR1)
218 #if defined(REG_R2) && !defined(NO_GLOBAL_REG_DECLS)
219 GLOBAL_REG_DECL(StgUnion,R2,REG_R2)
221 # define R2 (BaseReg->rR2)
224 #if defined(REG_R3) && !defined(NO_GLOBAL_REG_DECLS)
225 GLOBAL_REG_DECL(StgUnion,R3,REG_R3)
227 # define R3 (BaseReg->rR3)
230 #if defined(REG_R4) && !defined(NO_GLOBAL_REG_DECLS)
231 GLOBAL_REG_DECL(StgUnion,R4,REG_R4)
233 # define R4 (BaseReg->rR4)
236 #if defined(REG_R5) && !defined(NO_GLOBAL_REG_DECLS)
237 GLOBAL_REG_DECL(StgUnion,R5,REG_R5)
239 # define R5 (BaseReg->rR5)
242 #if defined(REG_R6) && !defined(NO_GLOBAL_REG_DECLS)
243 GLOBAL_REG_DECL(StgUnion,R6,REG_R6)
245 # define R6 (BaseReg->rR6)
248 #if defined(REG_R7) && !defined(NO_GLOBAL_REG_DECLS)
249 GLOBAL_REG_DECL(StgUnion,R7,REG_R7)
251 # define R7 (BaseReg->rR7)
254 #if defined(REG_R8) && !defined(NO_GLOBAL_REG_DECLS)
255 GLOBAL_REG_DECL(StgUnion,R8,REG_R8)
257 # define R8 (BaseReg->rR8)
260 #if defined(REG_R9) && !defined(NO_GLOBAL_REG_DECLS)
261 GLOBAL_REG_DECL(StgUnion,R9,REG_R9)
263 # define R9 (BaseReg->rR9)
266 #if defined(REG_R10) && !defined(NO_GLOBAL_REG_DECLS)
267 GLOBAL_REG_DECL(StgUnion,R10,REG_R10)
269 # define R10 (BaseReg->rR10)
272 #if defined(REG_F1) && !defined(NO_GLOBAL_REG_DECLS)
273 GLOBAL_REG_DECL(StgFloat,F1,REG_F1)
275 #define F1 (BaseReg->rF1)
278 #if defined(REG_F2) && !defined(NO_GLOBAL_REG_DECLS)
279 GLOBAL_REG_DECL(StgFloat,F2,REG_F2)
281 #define F2 (BaseReg->rF2)
284 #if defined(REG_F3) && !defined(NO_GLOBAL_REG_DECLS)
285 GLOBAL_REG_DECL(StgFloat,F3,REG_F3)
287 #define F3 (BaseReg->rF3)
290 #if defined(REG_F4) && !defined(NO_GLOBAL_REG_DECLS)
291 GLOBAL_REG_DECL(StgFloat,F4,REG_F4)
293 #define F4 (BaseReg->rF4)
296 #if defined(REG_D1) && !defined(NO_GLOBAL_REG_DECLS)
297 GLOBAL_REG_DECL(StgDouble,D1,REG_D1)
299 #define D1 (BaseReg->rD1)
302 #if defined(REG_D2) && !defined(NO_GLOBAL_REG_DECLS)
303 GLOBAL_REG_DECL(StgDouble,D2,REG_D2)
305 #define D2 (BaseReg->rD2)
308 #if defined(REG_L1) && !defined(NO_GLOBAL_REG_DECLS)
309 GLOBAL_REG_DECL(StgWord64,L1,REG_L1)
311 #define L1 (BaseReg->rL1)
315 * If BaseReg isn't mapped to a machine register, just use the global
316 * address of the current register table (CurrentRegTable in
317 * concurrent Haskell, MainRegTable otherwise).
320 #if defined(REG_Base) && !defined(NO_GLOBAL_REG_DECLS)
321 GLOBAL_REG_DECL(StgRegTable *,BaseReg,REG_Base)
324 #error BaseReg must be in a register for SMP
326 #define BaseReg (&((Capability *)MainCapability)[0].r)
329 #if defined(REG_Sp) && !defined(NO_GLOBAL_REG_DECLS)
330 GLOBAL_REG_DECL(P_,Sp,REG_Sp)
332 #define Sp (BaseReg->rSp)
335 #if defined(REG_SpLim) && !defined(NO_GLOBAL_REG_DECLS)
336 GLOBAL_REG_DECL(P_,SpLim,REG_SpLim)
338 #define SpLim (BaseReg->rSpLim)
341 #if defined(REG_Hp) && !defined(NO_GLOBAL_REG_DECLS)
342 GLOBAL_REG_DECL(P_,Hp,REG_Hp)
344 #define Hp (BaseReg->rHp)
347 #if defined(REG_HpLim) && !defined(NO_GLOBAL_REG_DECLS)
348 GLOBAL_REG_DECL(P_,HpLim,REG_HpLim)
350 #define HpLim (BaseReg->rHpLim)
353 #if defined(REG_CurrentTSO) && !defined(NO_GLOBAL_REG_DECLS)
354 GLOBAL_REG_DECL(struct _StgTSO *,CurrentTSO,REG_CurrentTSO)
356 #define CurrentTSO (BaseReg->rCurrentTSO)
359 #if defined(REG_CurrentNursery) && !defined(NO_GLOBAL_REG_DECLS)
360 GLOBAL_REG_DECL(bdescr *,CurrentNursery,REG_CurrentNursery)
362 #define CurrentNursery (BaseReg->rCurrentNursery)
365 #if defined(REG_HpAlloc) && !defined(NO_GLOBAL_REG_DECLS)
366 GLOBAL_REG_DECL(bdescr *,HpAlloc,REG_HpAlloc)
368 #define HpAlloc (BaseReg->rHpAlloc)
371 #if defined(REG_SparkHd) && !defined(NO_GLOBAL_REG_DECLS)
372 GLOBAL_REG_DECL(bdescr *,SparkHd,REG_SparkHd)
374 #define SparkHd (BaseReg->rSparks.hd)
377 #if defined(REG_SparkTl) && !defined(NO_GLOBAL_REG_DECLS)
378 GLOBAL_REG_DECL(bdescr *,SparkTl,REG_SparkTl)
380 #define SparkTl (BaseReg->rSparks.tl)
383 #if defined(REG_SparkBase) && !defined(NO_GLOBAL_REG_DECLS)
384 GLOBAL_REG_DECL(bdescr *,SparkBase,REG_SparkBase)
386 #define SparkBase (BaseReg->rSparks.base)
389 #if defined(REG_SparkLim) && !defined(NO_GLOBAL_REG_DECLS)
390 GLOBAL_REG_DECL(bdescr *,SparkLim,REG_SparkLim)
392 #define SparkLim (BaseReg->rSparks.lim)
395 /* -----------------------------------------------------------------------------
396 Get absolute function pointers from the register table, to save
405 as long as the offset is within the range of a signed byte
406 (-128..+127). So we pick some common absolute_addresses and put
407 them in the register table. As a bonus, linking time should also
410 Other possible candidates in order of importance:
413 stg_CAF_BLACKHOLE_info
416 anything else probably isn't worth the effort.
418 -------------------------------------------------------------------------- */
421 #define FunReg ((StgFunTable *)((void *)BaseReg - sizeof(StgFunTable)))
423 #define stg_gc_enter_1 (FunReg->stgGCEnter1)
424 #define stg_gc_fun (FunReg->stgGCFun)
426 /* -----------------------------------------------------------------------------
427 For any registers which are denoted "caller-saves" by the C calling
428 convention, we have to emit code to save and restore them across C
430 -------------------------------------------------------------------------- */
432 #ifdef CALLER_SAVES_R1
433 #define CALLER_SAVE_R1 SAVE_R1 = R1;
434 #define CALLER_RESTORE_R1 R1 = SAVE_R1;
436 #define CALLER_SAVE_R1 /* nothing */
437 #define CALLER_RESTORE_R1 /* nothing */
440 #ifdef CALLER_SAVES_R2
441 #define CALLER_SAVE_R2 SAVE_R2 = R2;
442 #define CALLER_RESTORE_R2 R2 = SAVE_R2;
444 #define CALLER_SAVE_R2 /* nothing */
445 #define CALLER_RESTORE_R2 /* nothing */
448 #ifdef CALLER_SAVES_R3
449 #define CALLER_SAVE_R3 SAVE_R3 = R3;
450 #define CALLER_RESTORE_R3 R3 = SAVE_R3;
452 #define CALLER_SAVE_R3 /* nothing */
453 #define CALLER_RESTORE_R3 /* nothing */
456 #ifdef CALLER_SAVES_R4
457 #define CALLER_SAVE_R4 SAVE_R4 = R4;
458 #define CALLER_RESTORE_R4 R4 = SAVE_R4;
460 #define CALLER_SAVE_R4 /* nothing */
461 #define CALLER_RESTORE_R4 /* nothing */
464 #ifdef CALLER_SAVES_R5
465 #define CALLER_SAVE_R5 SAVE_R5 = R5;
466 #define CALLER_RESTORE_R5 R5 = SAVE_R5;
468 #define CALLER_SAVE_R5 /* nothing */
469 #define CALLER_RESTORE_R5 /* nothing */
472 #ifdef CALLER_SAVES_R6
473 #define CALLER_SAVE_R6 SAVE_R6 = R6;
474 #define CALLER_RESTORE_R6 R6 = SAVE_R6;
476 #define CALLER_SAVE_R6 /* nothing */
477 #define CALLER_RESTORE_R6 /* nothing */
480 #ifdef CALLER_SAVES_R7
481 #define CALLER_SAVE_R7 SAVE_R7 = R7;
482 #define CALLER_RESTORE_R7 R7 = SAVE_R7;
484 #define CALLER_SAVE_R7 /* nothing */
485 #define CALLER_RESTORE_R7 /* nothing */
488 #ifdef CALLER_SAVES_R8
489 #define CALLER_SAVE_R8 SAVE_R8 = R8;
490 #define CALLER_RESTORE_R8 R8 = SAVE_R8;
492 #define CALLER_SAVE_R8 /* nothing */
493 #define CALLER_RESTORE_R8 /* nothing */
496 #ifdef CALLER_SAVES_R9
497 #define CALLER_SAVE_R9 SAVE_R9 = R9;
498 #define CALLER_RESTORE_R9 R9 = SAVE_R9;
500 #define CALLER_SAVE_R9 /* nothing */
501 #define CALLER_RESTORE_R9 /* nothing */
504 #ifdef CALLER_SAVES_R10
505 #define CALLER_SAVE_R10 SAVE_R10 = R10;
506 #define CALLER_RESTORE_R10 R10 = SAVE_R10;
508 #define CALLER_SAVE_R10 /* nothing */
509 #define CALLER_RESTORE_R10 /* nothing */
512 #ifdef CALLER_SAVES_F1
513 #define CALLER_SAVE_F1 SAVE_F1 = F1;
514 #define CALLER_RESTORE_F1 F1 = SAVE_F1;
516 #define CALLER_SAVE_F1 /* nothing */
517 #define CALLER_RESTORE_F1 /* nothing */
520 #ifdef CALLER_SAVES_F2
521 #define CALLER_SAVE_F2 SAVE_F2 = F2;
522 #define CALLER_RESTORE_F2 F2 = SAVE_F2;
524 #define CALLER_SAVE_F2 /* nothing */
525 #define CALLER_RESTORE_F2 /* nothing */
528 #ifdef CALLER_SAVES_F3
529 #define CALLER_SAVE_F3 SAVE_F3 = F3;
530 #define CALLER_RESTORE_F3 F3 = SAVE_F3;
532 #define CALLER_SAVE_F3 /* nothing */
533 #define CALLER_RESTORE_F3 /* nothing */
536 #ifdef CALLER_SAVES_F4
537 #define CALLER_SAVE_F4 SAVE_F4 = F4;
538 #define CALLER_RESTORE_F4 F4 = SAVE_F4;
540 #define CALLER_SAVE_F4 /* nothing */
541 #define CALLER_RESTORE_F4 /* nothing */
544 #ifdef CALLER_SAVES_D1
545 #define CALLER_SAVE_D1 SAVE_D1 = D1;
546 #define CALLER_RESTORE_D1 D1 = SAVE_D1;
548 #define CALLER_SAVE_D1 /* nothing */
549 #define CALLER_RESTORE_D1 /* nothing */
552 #ifdef CALLER_SAVES_D2
553 #define CALLER_SAVE_D2 SAVE_D2 = D2;
554 #define CALLER_RESTORE_D2 D2 = SAVE_D2;
556 #define CALLER_SAVE_D2 /* nothing */
557 #define CALLER_RESTORE_D2 /* nothing */
560 #ifdef CALLER_SAVES_L1
561 #define CALLER_SAVE_L1 SAVE_L1 = L1;
562 #define CALLER_RESTORE_L1 L1 = SAVE_L1;
564 #define CALLER_SAVE_L1 /* nothing */
565 #define CALLER_RESTORE_L1 /* nothing */
568 #ifdef CALLER_SAVES_Sp
569 #define CALLER_SAVE_Sp SAVE_Sp = Sp;
570 #define CALLER_RESTORE_Sp Sp = SAVE_Sp;
572 #define CALLER_SAVE_Sp /* nothing */
573 #define CALLER_RESTORE_Sp /* nothing */
576 #ifdef CALLER_SAVES_SpLim
577 #define CALLER_SAVE_SpLim SAVE_SpLim = SpLim;
578 #define CALLER_RESTORE_SpLim SpLim = SAVE_SpLim;
580 #define CALLER_SAVE_SpLim /* nothing */
581 #define CALLER_RESTORE_SpLim /* nothing */
584 #ifdef CALLER_SAVES_Hp
585 #define CALLER_SAVE_Hp SAVE_Hp = Hp;
586 #define CALLER_RESTORE_Hp Hp = SAVE_Hp;
588 #define CALLER_SAVE_Hp /* nothing */
589 #define CALLER_RESTORE_Hp /* nothing */
592 #ifdef CALLER_SAVES_HpLim
593 #define CALLER_SAVE_HpLim SAVE_HpLim = HpLim;
594 #define CALLER_RESTORE_HpLim HpLim = SAVE_HpLim;
596 #define CALLER_SAVE_HpLim /* nothing */
597 #define CALLER_RESTORE_HpLim /* nothing */
600 #ifdef CALLER_SAVES_Base
602 #error "Can't have caller-saved BaseReg with SMP"
604 #define CALLER_SAVE_Base /* nothing */
605 #define CALLER_RESTORE_Base BaseReg = &MainRegTable;
607 #define CALLER_SAVE_Base /* nothing */
608 #define CALLER_RESTORE_Base /* nothing */
611 #ifdef CALLER_SAVES_CurrentTSO
612 #define CALLER_SAVE_CurrentTSO SAVE_CurrentTSO = CurrentTSO;
613 #define CALLER_RESTORE_CurrentTSO CurrentTSO = SAVE_CurrentTSO;
615 #define CALLER_SAVE_CurrentTSO /* nothing */
616 #define CALLER_RESTORE_CurrentTSO /* nothing */
619 #ifdef CALLER_SAVES_CurrentNursery
620 #define CALLER_SAVE_CurrentNursery SAVE_CurrentNursery = CurrentNursery;
621 #define CALLER_RESTORE_CurrentNursery CurrentNursery = SAVE_CurrentNursery;
623 #define CALLER_SAVE_CurrentNursery /* nothing */
624 #define CALLER_RESTORE_CurrentNursery /* nothing */
627 #ifdef CALLER_SAVES_HpAlloc
628 #define CALLER_SAVE_HpAlloc SAVE_HpAlloc = HpAlloc;
629 #define CALLER_RESTORE_HpAlloc HpAlloc = SAVE_HpAlloc;
631 #define CALLER_SAVE_HpAlloc /* nothing */
632 #define CALLER_RESTORE_HpAlloc /* nothing */
635 #ifdef CALLER_SAVES_SparkHd
636 #define CALLER_SAVE_SparkHd SAVE_SparkHd = SparkHd;
637 #define CALLER_RESTORE_SparkHd SparkHd = SAVE_SparkHd;
639 #define CALLER_SAVE_SparkHd /* nothing */
640 #define CALLER_RESTORE_SparkHd /* nothing */
643 #ifdef CALLER_SAVES_SparkTl
644 #define CALLER_SAVE_SparkTl SAVE_SparkTl = SparkTl;
645 #define CALLER_RESTORE_SparkTl SparkTl = SAVE_SparkTl;
647 #define CALLER_SAVE_SparkTl /* nothing */
648 #define CALLER_RESTORE_SparkTl /* nothing */
651 #ifdef CALLER_SAVES_SparkBase
652 #define CALLER_SAVE_SparkBase SAVE_SparkBase = SparkBase;
653 #define CALLER_RESTORE_SparkBase SparkBase = SAVE_SparkBase;
655 #define CALLER_SAVE_SparkBase /* nothing */
656 #define CALLER_RESTORE_SparkBase /* nothing */
659 #ifdef CALLER_SAVES_SparkLim
660 #define CALLER_SAVE_SparkLim SAVE_SparkLim = SparkLim;
661 #define CALLER_RESTORE_SparkLim SparkLim = SAVE_SparkLim;
663 #define CALLER_SAVE_SparkLim /* nothing */
664 #define CALLER_RESTORE_SparkLim /* nothing */
667 #endif /* IN_STG_CODE */
669 /* ----------------------------------------------------------------------------
670 Handy bunches of saves/restores
671 ------------------------------------------------------------------------ */
675 #define CALLER_SAVE_USER \
692 /* Save Base last, since the others may
693 be addressed relative to it */
694 #define CALLER_SAVE_SYSTEM \
699 CALLER_SAVE_CurrentTSO \
700 CALLER_SAVE_CurrentNursery \
701 CALLER_SAVE_SparkHd \
702 CALLER_SAVE_SparkTl \
703 CALLER_SAVE_SparkBase \
704 CALLER_SAVE_SparkLim \
707 #define CALLER_RESTORE_USER \
724 /* Restore Base first, since the others may
725 be addressed relative to it */
726 #define CALLER_RESTORE_SYSTEM \
727 CALLER_RESTORE_Base \
729 CALLER_RESTORE_SpLim \
731 CALLER_RESTORE_HpLim \
732 CALLER_RESTORE_CurrentTSO \
733 CALLER_RESTORE_CurrentNursery \
734 CALLER_RESTORE_SparkHd \
735 CALLER_RESTORE_SparkTl \
736 CALLER_RESTORE_SparkBase \
737 CALLER_RESTORE_SparkLim
739 #else /* not IN_STG_CODE */
741 #define CALLER_SAVE_USER /* nothing */
742 #define CALLER_SAVE_SYSTEM /* nothing */
743 #define CALLER_RESTORE_USER /* nothing */
744 #define CALLER_RESTORE_SYSTEM /* nothing */
746 #endif /* IN_STG_CODE */
747 #define CALLER_SAVE_ALL \
751 #define CALLER_RESTORE_ALL \
752 CALLER_RESTORE_SYSTEM \