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 #if defined(SMP) || defined(PAR)
163 #define SAVE_SparkHd (BaseReg->rSparks.hd)
164 #define SAVE_SparkTl (BaseReg->rSparks.tl)
165 #define SAVE_SparkBase (BaseReg->rSparks.base)
166 #define SAVE_SparkLim (BaseReg->rSparks.lim)
169 /* We sometimes need to save registers across a C-call, eg. if they
170 * are clobbered in the standard calling convention. We define the
171 * save locations for all registers in the register table.
174 #define SAVE_R1 (BaseReg->rR1)
175 #define SAVE_R2 (BaseReg->rR2)
176 #define SAVE_R3 (BaseReg->rR3)
177 #define SAVE_R4 (BaseReg->rR4)
178 #define SAVE_R5 (BaseReg->rR5)
179 #define SAVE_R6 (BaseReg->rR6)
180 #define SAVE_R7 (BaseReg->rR7)
181 #define SAVE_R8 (BaseReg->rR8)
183 #define SAVE_F1 (BaseReg->rF1)
184 #define SAVE_F2 (BaseReg->rF2)
185 #define SAVE_F3 (BaseReg->rF3)
186 #define SAVE_F4 (BaseReg->rF4)
188 #define SAVE_D1 (BaseReg->rD1)
189 #define SAVE_D2 (BaseReg->rD2)
191 #define SAVE_L1 (BaseReg->rL1)
193 /* -----------------------------------------------------------------------------
194 * Emit the GCC-specific register declarations for each machine
195 * register being used. If any STG register isn't mapped to a machine
196 * register, then map it to an offset from BaseReg.
198 * First, the general purpose registers. The idea is, if a particular
199 * general-purpose STG register can't be mapped to a real machine
200 * register, it won't be used at all. Instead, we'll use the stack.
202 * This is an improvement on the way things used to be done, when all
203 * registers were mapped to locations in the register table, and stuff
204 * was being shifted from the stack to the register table and back
205 * again for no good reason (on register-poor architectures).
208 #define GLOBAL_REG_DECL(type,name,reg) register type name REG(reg);
211 GLOBAL_REG_DECL(StgUnion,R1,REG_R1)
213 #define R1 (BaseReg->rR1)
217 GLOBAL_REG_DECL(StgUnion,R2,REG_R2)
219 #define R2 (BaseReg->rR2)
223 GLOBAL_REG_DECL(StgUnion,R3,REG_R3)
225 # define R3 (BaseReg->rR3)
229 GLOBAL_REG_DECL(StgUnion,R4,REG_R4)
231 # define R4 (BaseReg->rR4)
235 GLOBAL_REG_DECL(StgUnion,R5,REG_R5)
237 # define R5 (BaseReg->rR5)
241 GLOBAL_REG_DECL(StgUnion,R6,REG_R6)
243 # define R6 (BaseReg->rR6)
247 GLOBAL_REG_DECL(StgUnion,R7,REG_R7)
249 # define R7 (BaseReg->rR7)
253 GLOBAL_REG_DECL(StgUnion,R8,REG_R8)
255 # define R8 (BaseReg->rR8)
259 GLOBAL_REG_DECL(StgUnion,R9,REG_R9)
261 # define R9 (BaseReg->rR9)
265 GLOBAL_REG_DECL(StgUnion,R10,REG_R10)
267 # define R10 (BaseReg->rR10)
271 GLOBAL_REG_DECL(StgFloat,F1,REG_F1)
273 #define F1 (BaseReg->rF1)
277 GLOBAL_REG_DECL(StgFloat,F2,REG_F2)
279 #define F2 (BaseReg->rF2)
283 GLOBAL_REG_DECL(StgFloat,F3,REG_F3)
285 #define F3 (BaseReg->rF3)
289 GLOBAL_REG_DECL(StgFloat,F4,REG_F4)
291 #define F4 (BaseReg->rF4)
295 GLOBAL_REG_DECL(StgDouble,D1,REG_D1)
297 #define D1 (BaseReg->rD1)
301 GLOBAL_REG_DECL(StgDouble,D2,REG_D2)
303 #define D2 (BaseReg->rD2)
307 GLOBAL_REG_DECL(StgWord64,L1,REG_L1)
309 #define L1 (BaseReg->rL1)
313 * If BaseReg isn't mapped to a machine register, just use the global
314 * address of the current register table (CurrentRegTable in
315 * concurrent Haskell, MainRegTable otherwise).
319 GLOBAL_REG_DECL(StgRegTable *,BaseReg,REG_Base)
322 #error BaseReg must be in a register for SMP
324 #define BaseReg (&((Capability *)MainCapability)[0].r)
328 GLOBAL_REG_DECL(P_,Sp,REG_Sp)
330 #define Sp (BaseReg->rSp)
334 GLOBAL_REG_DECL(P_,SpLim,REG_SpLim)
336 #define SpLim (BaseReg->rSpLim)
340 GLOBAL_REG_DECL(P_,Hp,REG_Hp)
342 #define Hp (BaseReg->rHp)
346 GLOBAL_REG_DECL(P_,HpLim,REG_HpLim)
348 #define HpLim (BaseReg->rHpLim)
351 #ifdef REG_CurrentTSO
352 GLOBAL_REG_DECL(struct _StgTSO *,CurrentTSO,REG_CurrentTSO)
354 #define CurrentTSO (BaseReg->rCurrentTSO)
357 #ifdef REG_CurrentNursery
358 GLOBAL_REG_DECL(bdescr *,CurrentNursery,REG_CurrentNursery)
360 #define CurrentNursery (BaseReg->rCurrentNursery)
364 GLOBAL_REG_DECL(bdescr *,HpAlloc,REG_HpAlloc)
366 #define HpAlloc (BaseReg->rHpAlloc)
370 GLOBAL_REG_DECL(bdescr *,SparkHd,REG_SparkHd)
372 #define SparkHd (BaseReg->rSparks.hd)
376 GLOBAL_REG_DECL(bdescr *,SparkTl,REG_SparkTl)
378 #define SparkTl (BaseReg->rSparks.tl)
382 GLOBAL_REG_DECL(bdescr *,SparkBase,REG_SparkBase)
384 #define SparkBase (BaseReg->rSparks.base)
388 GLOBAL_REG_DECL(bdescr *,SparkLim,REG_SparkLim)
390 #define SparkLim (BaseReg->rSparks.lim)
393 /* -----------------------------------------------------------------------------
394 Get absolute function pointers from the register table, to save
403 as long as the offset is within the range of a signed byte
404 (-128..+127). So we pick some common absolute_addresses and put
405 them in the register table. As a bonus, linking time should also
408 Other possible candidates in order of importance:
411 stg_CAF_BLACKHOLE_info
414 anything else probably isn't worth the effort.
416 -------------------------------------------------------------------------- */
419 #define FunReg ((StgFunTable *)((void *)BaseReg - sizeof(StgFunTable)))
421 #define stg_gc_enter_1 (FunReg->stgGCEnter1)
422 #define stg_gc_fun (FunReg->stgGCFun)
424 /* -----------------------------------------------------------------------------
425 For any registers which are denoted "caller-saves" by the C calling
426 convention, we have to emit code to save and restore them across C
428 -------------------------------------------------------------------------- */
430 #ifdef CALLER_SAVES_R1
431 #define CALLER_SAVE_R1 SAVE_R1 = R1;
432 #define CALLER_RESTORE_R1 R1 = SAVE_R1;
434 #define CALLER_SAVE_R1 /* nothing */
435 #define CALLER_RESTORE_R1 /* nothing */
438 #ifdef CALLER_SAVES_R2
439 #define CALLER_SAVE_R2 SAVE_R2 = R2;
440 #define CALLER_RESTORE_R2 R2 = SAVE_R2;
442 #define CALLER_SAVE_R2 /* nothing */
443 #define CALLER_RESTORE_R2 /* nothing */
446 #ifdef CALLER_SAVES_R3
447 #define CALLER_SAVE_R3 SAVE_R3 = R3;
448 #define CALLER_RESTORE_R3 R3 = SAVE_R3;
450 #define CALLER_SAVE_R3 /* nothing */
451 #define CALLER_RESTORE_R3 /* nothing */
454 #ifdef CALLER_SAVES_R4
455 #define CALLER_SAVE_R4 SAVE_R4 = R4;
456 #define CALLER_RESTORE_R4 R4 = SAVE_R4;
458 #define CALLER_SAVE_R4 /* nothing */
459 #define CALLER_RESTORE_R4 /* nothing */
462 #ifdef CALLER_SAVES_R5
463 #define CALLER_SAVE_R5 SAVE_R5 = R5;
464 #define CALLER_RESTORE_R5 R5 = SAVE_R5;
466 #define CALLER_SAVE_R5 /* nothing */
467 #define CALLER_RESTORE_R5 /* nothing */
470 #ifdef CALLER_SAVES_R6
471 #define CALLER_SAVE_R6 SAVE_R6 = R6;
472 #define CALLER_RESTORE_R6 R6 = SAVE_R6;
474 #define CALLER_SAVE_R6 /* nothing */
475 #define CALLER_RESTORE_R6 /* nothing */
478 #ifdef CALLER_SAVES_R7
479 #define CALLER_SAVE_R7 SAVE_R7 = R7;
480 #define CALLER_RESTORE_R7 R7 = SAVE_R7;
482 #define CALLER_SAVE_R7 /* nothing */
483 #define CALLER_RESTORE_R7 /* nothing */
486 #ifdef CALLER_SAVES_R8
487 #define CALLER_SAVE_R8 SAVE_R8 = R8;
488 #define CALLER_RESTORE_R8 R8 = SAVE_R8;
490 #define CALLER_SAVE_R8 /* nothing */
491 #define CALLER_RESTORE_R8 /* nothing */
494 #ifdef CALLER_SAVES_R9
495 #define CALLER_SAVE_R9 SAVE_R9 = R9;
496 #define CALLER_RESTORE_R9 R9 = SAVE_R9;
498 #define CALLER_SAVE_R9 /* nothing */
499 #define CALLER_RESTORE_R9 /* nothing */
502 #ifdef CALLER_SAVES_R10
503 #define CALLER_SAVE_R10 SAVE_R10 = R10;
504 #define CALLER_RESTORE_R10 R10 = SAVE_R10;
506 #define CALLER_SAVE_R10 /* nothing */
507 #define CALLER_RESTORE_R10 /* nothing */
510 #ifdef CALLER_SAVES_F1
511 #define CALLER_SAVE_F1 SAVE_F1 = F1;
512 #define CALLER_RESTORE_F1 F1 = SAVE_F1;
514 #define CALLER_SAVE_F1 /* nothing */
515 #define CALLER_RESTORE_F1 /* nothing */
518 #ifdef CALLER_SAVES_F2
519 #define CALLER_SAVE_F2 SAVE_F2 = F2;
520 #define CALLER_RESTORE_F2 F2 = SAVE_F2;
522 #define CALLER_SAVE_F2 /* nothing */
523 #define CALLER_RESTORE_F2 /* nothing */
526 #ifdef CALLER_SAVES_F3
527 #define CALLER_SAVE_F3 SAVE_F3 = F3;
528 #define CALLER_RESTORE_F3 F3 = SAVE_F3;
530 #define CALLER_SAVE_F3 /* nothing */
531 #define CALLER_RESTORE_F3 /* nothing */
534 #ifdef CALLER_SAVES_F4
535 #define CALLER_SAVE_F4 SAVE_F4 = F4;
536 #define CALLER_RESTORE_F4 F4 = SAVE_F4;
538 #define CALLER_SAVE_F4 /* nothing */
539 #define CALLER_RESTORE_F4 /* nothing */
542 #ifdef CALLER_SAVES_D1
543 #define CALLER_SAVE_D1 SAVE_D1 = D1;
544 #define CALLER_RESTORE_D1 D1 = SAVE_D1;
546 #define CALLER_SAVE_D1 /* nothing */
547 #define CALLER_RESTORE_D1 /* nothing */
550 #ifdef CALLER_SAVES_D2
551 #define CALLER_SAVE_D2 SAVE_D2 = D2;
552 #define CALLER_RESTORE_D2 D2 = SAVE_D2;
554 #define CALLER_SAVE_D2 /* nothing */
555 #define CALLER_RESTORE_D2 /* nothing */
558 #ifdef CALLER_SAVES_L1
559 #define CALLER_SAVE_L1 SAVE_L1 = L1;
560 #define CALLER_RESTORE_L1 L1 = SAVE_L1;
562 #define CALLER_SAVE_L1 /* nothing */
563 #define CALLER_RESTORE_L1 /* nothing */
566 #ifdef CALLER_SAVES_Sp
567 #define CALLER_SAVE_Sp SAVE_Sp = Sp;
568 #define CALLER_RESTORE_Sp Sp = SAVE_Sp;
570 #define CALLER_SAVE_Sp /* nothing */
571 #define CALLER_RESTORE_Sp /* nothing */
574 #ifdef CALLER_SAVES_SpLim
575 #define CALLER_SAVE_SpLim SAVE_SpLim = SpLim;
576 #define CALLER_RESTORE_SpLim SpLim = SAVE_SpLim;
578 #define CALLER_SAVE_SpLim /* nothing */
579 #define CALLER_RESTORE_SpLim /* nothing */
582 #ifdef CALLER_SAVES_Hp
583 #define CALLER_SAVE_Hp SAVE_Hp = Hp;
584 #define CALLER_RESTORE_Hp Hp = SAVE_Hp;
586 #define CALLER_SAVE_Hp /* nothing */
587 #define CALLER_RESTORE_Hp /* nothing */
590 #ifdef CALLER_SAVES_HpLim
591 #define CALLER_SAVE_HpLim SAVE_HpLim = HpLim;
592 #define CALLER_RESTORE_HpLim HpLim = SAVE_HpLim;
594 #define CALLER_SAVE_HpLim /* nothing */
595 #define CALLER_RESTORE_HpLim /* nothing */
598 #ifdef CALLER_SAVES_Base
600 #error "Can't have caller-saved BaseReg with SMP"
602 #define CALLER_SAVE_Base /* nothing */
603 #define CALLER_RESTORE_Base BaseReg = &MainRegTable;
605 #define CALLER_SAVE_Base /* nothing */
606 #define CALLER_RESTORE_Base /* nothing */
609 #ifdef CALLER_SAVES_CurrentTSO
610 #define CALLER_SAVE_CurrentTSO SAVE_CurrentTSO = CurrentTSO;
611 #define CALLER_RESTORE_CurrentTSO CurrentTSO = SAVE_CurrentTSO;
613 #define CALLER_SAVE_CurrentTSO /* nothing */
614 #define CALLER_RESTORE_CurrentTSO /* nothing */
617 #ifdef CALLER_SAVES_CurrentNursery
618 #define CALLER_SAVE_CurrentNursery SAVE_CurrentNursery = CurrentNursery;
619 #define CALLER_RESTORE_CurrentNursery CurrentNursery = SAVE_CurrentNursery;
621 #define CALLER_SAVE_CurrentNursery /* nothing */
622 #define CALLER_RESTORE_CurrentNursery /* nothing */
625 #ifdef CALLER_SAVES_HpAlloc
626 #define CALLER_SAVE_HpAlloc SAVE_HpAlloc = HpAlloc;
627 #define CALLER_RESTORE_HpAlloc HpAlloc = SAVE_HpAlloc;
629 #define CALLER_SAVE_HpAlloc /* nothing */
630 #define CALLER_RESTORE_HpAlloc /* nothing */
633 #ifdef CALLER_SAVES_SparkHd
634 #define CALLER_SAVE_SparkHd SAVE_SparkHd = SparkHd;
635 #define CALLER_RESTORE_SparkHd SparkHd = SAVE_SparkHd;
637 #define CALLER_SAVE_SparkHd /* nothing */
638 #define CALLER_RESTORE_SparkHd /* nothing */
641 #ifdef CALLER_SAVES_SparkTl
642 #define CALLER_SAVE_SparkTl SAVE_SparkTl = SparkTl;
643 #define CALLER_RESTORE_SparkTl SparkTl = SAVE_SparkTl;
645 #define CALLER_SAVE_SparkTl /* nothing */
646 #define CALLER_RESTORE_SparkTl /* nothing */
649 #ifdef CALLER_SAVES_SparkBase
650 #define CALLER_SAVE_SparkBase SAVE_SparkBase = SparkBase;
651 #define CALLER_RESTORE_SparkBase SparkBase = SAVE_SparkBase;
653 #define CALLER_SAVE_SparkBase /* nothing */
654 #define CALLER_RESTORE_SparkBase /* nothing */
657 #ifdef CALLER_SAVES_SparkLim
658 #define CALLER_SAVE_SparkLim SAVE_SparkLim = SparkLim;
659 #define CALLER_RESTORE_SparkLim SparkLim = SAVE_SparkLim;
661 #define CALLER_SAVE_SparkLim /* nothing */
662 #define CALLER_RESTORE_SparkLim /* nothing */
665 #endif /* IN_STG_CODE */
667 /* ----------------------------------------------------------------------------
668 Handy bunches of saves/restores
669 ------------------------------------------------------------------------ */
673 #define CALLER_SAVE_USER \
690 /* Save Base last, since the others may
691 be addressed relative to it */
692 #define CALLER_SAVE_SYSTEM \
697 CALLER_SAVE_CurrentTSO \
698 CALLER_SAVE_CurrentNursery \
699 CALLER_SAVE_SparkHd \
700 CALLER_SAVE_SparkTl \
701 CALLER_SAVE_SparkBase \
702 CALLER_SAVE_SparkLim \
705 #define CALLER_RESTORE_USER \
722 /* Restore Base first, since the others may
723 be addressed relative to it */
724 #define CALLER_RESTORE_SYSTEM \
725 CALLER_RESTORE_Base \
727 CALLER_RESTORE_SpLim \
729 CALLER_RESTORE_HpLim \
730 CALLER_RESTORE_CurrentTSO \
731 CALLER_RESTORE_CurrentNursery \
732 CALLER_RESTORE_SparkHd \
733 CALLER_RESTORE_SparkTl \
734 CALLER_RESTORE_SparkBase \
735 CALLER_RESTORE_SparkLim
737 #else /* not IN_STG_CODE */
739 #define CALLER_SAVE_USER /* nothing */
740 #define CALLER_SAVE_SYSTEM /* nothing */
741 #define CALLER_RESTORE_USER /* nothing */
742 #define CALLER_RESTORE_SYSTEM /* nothing */
744 #endif /* IN_STG_CODE */
745 #define CALLER_SAVE_ALL \
749 #define CALLER_RESTORE_ALL \
750 CALLER_RESTORE_SYSTEM \