includes/stg/Regs.h

   1 /* -----------------------------------------------------------------------------
   2  *
   3  * (c) The GHC Team, 1998-2009
   4  *
   5  * Registers in the STG machine.
   6  *
   7  * Do not #include this file directly: #include "Rts.h" instead.
   8  *
   9  * To understand the structure of the RTS headers, see the wiki:
  10  *   http://hackage.haskell.org/trac/ghc/wiki/Commentary/SourceTree/Includes
  11  *
  12  * ---------------------------------------------------------------------------*/
  13
  14 #ifndef REGS_H
  15 #define REGS_H
  16
  17 /*
  18  * The STG machine has a collection of "registers", each one of which
  19  * may or may not correspond to an actual machine register when
  20  * running code.
  21  *
  22  * The register set is backed by a table in memory (struct
  23  * StgRegTable).  If a particular STG register is not mapped to a
  24  * machine register, then the apprpriate slot in this table is used
  25  * instead.
  26  *
  27  * This table is itself pointed to by another register, BaseReg.  If
  28  * BaseReg is not in a machine register, then the register table is
  29  * used from an absolute location (MainCapability).
  30  *
  31  */
  32
  33 typedef struct {
  34   StgWord        stgEagerBlackholeInfo;
  35   StgFunPtr      stgGCEnter1;
  36   StgFunPtr      stgGCFun;
  37 } StgFunTable;
  38
  39 /*
  40  * Vanilla registers are given this union type, which is purely so
  41  * that we can cast the vanilla reg to a variety of types with the
  42  * minimum of syntax.  eg.  R1.w instead of (StgWord)R1.
  43  */
  44 typedef union {
  45     StgWord        w;
  46     StgAddr        a;
  47     StgChar        c;
  48     StgFloat       f;
  49     StgInt         i;
  50     StgPtr         p;
  51 } StgUnion;
  52
  53 /*
  54  * This is the table that holds shadow-locations for all the STG
  55  * registers.  The shadow locations are used when:
  56  *
  57  *     1) the particular register isn't mapped to a real machine
  58  *        register, probably because there's a shortage of real registers.
  59  *     2) caller-saves registers are saved across a CCall
  60  */
  61 typedef struct StgRegTable_ {
  62   StgUnion        rR1;
  63   StgUnion        rR2;
  64   StgUnion        rR3;
  65   StgUnion        rR4;
  66   StgUnion        rR5;
  67   StgUnion        rR6;
  68   StgUnion        rR7;
  69   StgUnion        rR8;
  70   StgUnion        rR9;          /* used occasionally by heap/stack checks */
  71   StgUnion        rR10;         /* used occasionally by heap/stack checks */
  72   StgFloat        rF1;
  73   StgFloat        rF2;
  74   StgFloat        rF3;
  75   StgFloat        rF4;
  76   StgDouble       rD1;
  77   StgDouble       rD2;
  78   StgWord64       rL1;
  79   StgPtr          rSp;
  80   StgPtr          rSpLim;
  81   StgPtr          rHp;
  82   StgPtr          rHpLim;
  83   struct StgTSO_ *rCurrentTSO;
  84   struct step_   *rNursery;
  85   struct bdescr_ *rCurrentNursery; /* Hp/HpLim point into this block */
  86   struct bdescr_ *rCurrentAlloc;   /* for allocation using allocate() */
  87   StgWord         rHpAlloc;     /* number of *bytes* being allocated in heap */
  88   StgWord         rRet;  // holds the return code of the thread
  89 } StgRegTable;
  90
  91 #if IN_STG_CODE
  92
  93 /*
  94  * Registers Hp and HpLim are global across the entire system, and are
  95  * copied into the RegTable before executing a thread.
  96  *
  97  * Registers Sp and SpLim are saved in the TSO for the
  98  * thread, but are copied into the RegTable before executing a thread.
  99  *
 100  * All other registers are "general purpose", and are used for passing
 101  * arguments to functions, and returning values.  The code generator
 102  * knows how many of these are in real registers, and avoids
 103  * generating code that uses non-real registers.  General purpose
 104  * registers are never saved when returning to the scheduler, instead
 105  * we save whatever is live at the time on the stack, and restore it
 106  * later.  This should reduce the context switch time, amongst other
 107  * things.
 108  *
 109  * For argument passing, the stack will be used in preference to
 110  * pseudo-registers if the architecture has too few general purpose
 111  * registers.
 112  *
 113  * Some special RTS functions like newArray and the Integer primitives
 114  * expect their arguments to be in registers R1-Rn, so we use these
 115  * (pseudo-)registers in those cases.
 116  */
 117
 118 /*
 119  * Locations for saving per-thread registers.
 120  */
 121
 122 #define SAVE_Sp             (CurrentTSO->sp)
 123 #define SAVE_SpLim          (CurrentTSO->splim)
 124
 125 #define SAVE_Hp             (BaseReg->rHp)
 126
 127 #define SAVE_CurrentTSO     (BaseReg->rCurrentTSO)
 128 #define SAVE_CurrentNursery (BaseReg->rCurrentNursery)
 129 #define SAVE_HpAlloc        (BaseReg->rHpAlloc)
 130
 131 /* We sometimes need to save registers across a C-call, eg. if they
 132  * are clobbered in the standard calling convention.  We define the
 133  * save locations for all registers in the register table.
 134  */
 135
 136 #define SAVE_R1             (BaseReg->rR1)
 137 #define SAVE_R2             (BaseReg->rR2)
 138 #define SAVE_R3             (BaseReg->rR3)
 139 #define SAVE_R4             (BaseReg->rR4)
 140 #define SAVE_R5             (BaseReg->rR5)
 141 #define SAVE_R6             (BaseReg->rR6)
 142 #define SAVE_R7             (BaseReg->rR7)
 143 #define SAVE_R8             (BaseReg->rR8)
 144
 145 #define SAVE_F1             (BaseReg->rF1)
 146 #define SAVE_F2             (BaseReg->rF2)
 147 #define SAVE_F3             (BaseReg->rF3)
 148 #define SAVE_F4             (BaseReg->rF4)
 149
 150 #define SAVE_D1             (BaseReg->rD1)
 151 #define SAVE_D2             (BaseReg->rD2)
 152
 153 #define SAVE_L1             (BaseReg->rL1)
 154
 155 /* -----------------------------------------------------------------------------
 156  * Emit the GCC-specific register declarations for each machine
 157  * register being used.  If any STG register isn't mapped to a machine
 158  * register, then map it to an offset from BaseReg.
 159  *
 160  * First, the general purpose registers.  The idea is, if a particular
 161  * general-purpose STG register can't be mapped to a real machine
 162  * register, it won't be used at all.  Instead, we'll use the stack.
 163  *
 164  * This is an improvement on the way things used to be done, when all
 165  * registers were mapped to locations in the register table, and stuff
 166  * was being shifted from the stack to the register table and back
 167  * again for no good reason (on register-poor architectures).
 168  */
 169
 170 /* define NO_REGS to omit register declarations - used in RTS C code
 171  * that needs all the STG definitions but not the global register
 172  * settings.
 173  */
 174 #define GLOBAL_REG_DECL(type,name,reg) register type name REG(reg);
 175
 176 #if defined(REG_R1) && !defined(NO_GLOBAL_REG_DECLS)
 177 GLOBAL_REG_DECL(StgUnion,R1,REG_R1)
 178 #else
 179 # define R1 (BaseReg->rR1)
 180 #endif
 181
 182 #if defined(REG_R2) && !defined(NO_GLOBAL_REG_DECLS)
 183 GLOBAL_REG_DECL(StgUnion,R2,REG_R2)
 184 #else
 185 # define R2 (BaseReg->rR2)
 186 #endif
 187
 188 #if defined(REG_R3) && !defined(NO_GLOBAL_REG_DECLS)
 189 GLOBAL_REG_DECL(StgUnion,R3,REG_R3)
 190 #else
 191 # define R3 (BaseReg->rR3)
 192 #endif
 193
 194 #if defined(REG_R4) && !defined(NO_GLOBAL_REG_DECLS)
 195 GLOBAL_REG_DECL(StgUnion,R4,REG_R4)
 196 #else
 197 # define R4 (BaseReg->rR4)
 198 #endif
 199
 200 #if defined(REG_R5) && !defined(NO_GLOBAL_REG_DECLS)
 201 GLOBAL_REG_DECL(StgUnion,R5,REG_R5)
 202 #else
 203 # define R5 (BaseReg->rR5)
 204 #endif
 205
 206 #if defined(REG_R6) && !defined(NO_GLOBAL_REG_DECLS)
 207 GLOBAL_REG_DECL(StgUnion,R6,REG_R6)
 208 #else
 209 # define R6 (BaseReg->rR6)
 210 #endif
 211
 212 #if defined(REG_R7) && !defined(NO_GLOBAL_REG_DECLS)
 213 GLOBAL_REG_DECL(StgUnion,R7,REG_R7)
 214 #else
 215 # define R7 (BaseReg->rR7)
 216 #endif
 217
 218 #if defined(REG_R8) && !defined(NO_GLOBAL_REG_DECLS)
 219 GLOBAL_REG_DECL(StgUnion,R8,REG_R8)
 220 #else
 221 # define R8 (BaseReg->rR8)
 222 #endif
 223
 224 #if defined(REG_R9) && !defined(NO_GLOBAL_REG_DECLS)
 225 GLOBAL_REG_DECL(StgUnion,R9,REG_R9)
 226 #else
 227 # define R9 (BaseReg->rR9)
 228 #endif
 229
 230 #if defined(REG_R10) && !defined(NO_GLOBAL_REG_DECLS)
 231 GLOBAL_REG_DECL(StgUnion,R10,REG_R10)
 232 #else
 233 # define R10 (BaseReg->rR10)
 234 #endif
 235
 236 #if defined(REG_F1) && !defined(NO_GLOBAL_REG_DECLS)
 237 GLOBAL_REG_DECL(StgFloat,F1,REG_F1)
 238 #else
 239 #define F1 (BaseReg->rF1)
 240 #endif
 241
 242 #if defined(REG_F2) && !defined(NO_GLOBAL_REG_DECLS)
 243 GLOBAL_REG_DECL(StgFloat,F2,REG_F2)
 244 #else
 245 #define F2 (BaseReg->rF2)
 246 #endif
 247
 248 #if defined(REG_F3) && !defined(NO_GLOBAL_REG_DECLS)
 249 GLOBAL_REG_DECL(StgFloat,F3,REG_F3)
 250 #else
 251 #define F3 (BaseReg->rF3)
 252 #endif
 253
 254 #if defined(REG_F4) && !defined(NO_GLOBAL_REG_DECLS)
 255 GLOBAL_REG_DECL(StgFloat,F4,REG_F4)
 256 #else
 257 #define F4 (BaseReg->rF4)
 258 #endif
 259
 260 #if defined(REG_D1) && !defined(NO_GLOBAL_REG_DECLS)
 261 GLOBAL_REG_DECL(StgDouble,D1,REG_D1)
 262 #else
 263 #define D1 (BaseReg->rD1)
 264 #endif
 265
 266 #if defined(REG_D2) && !defined(NO_GLOBAL_REG_DECLS)
 267 GLOBAL_REG_DECL(StgDouble,D2,REG_D2)
 268 #else
 269 #define D2 (BaseReg->rD2)
 270 #endif
 271
 272 #if defined(REG_L1) && !defined(NO_GLOBAL_REG_DECLS)
 273 GLOBAL_REG_DECL(StgWord64,L1,REG_L1)
 274 #else
 275 #define L1 (BaseReg->rL1)
 276 #endif
 277
 278 /*
 279  * If BaseReg isn't mapped to a machine register, just use the global
 280  * address of the current register table (CurrentRegTable in
 281  * concurrent Haskell, MainRegTable otherwise).
 282  */
 283
 284 /* A capability is a combination of a FunTable and a RegTable.  In STG
 285  * code, BaseReg normally points to the RegTable portion of this
 286  * structure, so that we can index both forwards and backwards to take
 287  * advantage of shorter instruction forms on some archs (eg. x86).
 288  * This is a cut-down version of the Capability structure; the full
 289  * version is defined in Capability.h.
 290  */
 291 struct PartCapability_ {
 292     StgFunTable f;
 293     StgRegTable r;
 294 };
 295
 296 /* No such thing as a MainCapability under THREADED_RTS - each thread must have
 297  * its own Capability.
 298  */
 299 #if IN_STG_CODE && !(defined(THREADED_RTS) && !defined(NOSMP))
 300 extern W_ MainCapability[];
 301 #endif
 302
 303 /*
 304  * Assigning to BaseReg (the ASSIGN_BaseReg macro): this happens on
 305  * return from a "safe" foreign call, when the thread might be running
 306  * on a new Capability.  Obviously if BaseReg is not a register, then
 307  * we are restricted to a single Capability (this invariant is enforced
 308  * in Capability.c:initCapabilities), and assigning to BaseReg can be omitted.
 309  */
 310
 311 #if defined(REG_Base) && !defined(NO_GLOBAL_REG_DECLS)
 312 GLOBAL_REG_DECL(StgRegTable *,BaseReg,REG_Base)
 313 #define ASSIGN_BaseReg(e) (BaseReg = (e))
 314 #else
 315 #if defined(THREADED_RTS) && !defined(NOSMP)
 316 #error BaseReg must be in a register for THREADED_RTS
 317 #endif
 318 #define BaseReg (&((struct PartCapability_ *)MainCapability)->r)
 319 #define ASSIGN_BaseReg(e) (e)
 320 #endif
 321
 322 #if defined(REG_Sp) && !defined(NO_GLOBAL_REG_DECLS)
 323 GLOBAL_REG_DECL(P_,Sp,REG_Sp)
 324 #else
 325 #define Sp (BaseReg->rSp)
 326 #endif
 327
 328 #if defined(REG_SpLim) && !defined(NO_GLOBAL_REG_DECLS)
 329 GLOBAL_REG_DECL(P_,SpLim,REG_SpLim)
 330 #else
 331 #define SpLim (BaseReg->rSpLim)
 332 #endif
 333
 334 #if defined(REG_Hp) && !defined(NO_GLOBAL_REG_DECLS)
 335 GLOBAL_REG_DECL(P_,Hp,REG_Hp)
 336 #else
 337 #define Hp (BaseReg->rHp)
 338 #endif
 339
 340 #if defined(REG_HpLim) && !defined(NO_GLOBAL_REG_DECLS)
 341 #error HpLim cannot be in a register
 342 #else
 343 #define HpLim (BaseReg->rHpLim)
 344 #endif
 345
 346 #if defined(REG_CurrentTSO) && !defined(NO_GLOBAL_REG_DECLS)
 347 GLOBAL_REG_DECL(struct _StgTSO *,CurrentTSO,REG_CurrentTSO)
 348 #else
 349 #define CurrentTSO (BaseReg->rCurrentTSO)
 350 #endif
 351
 352 #if defined(REG_CurrentNursery) && !defined(NO_GLOBAL_REG_DECLS)
 353 GLOBAL_REG_DECL(bdescr *,CurrentNursery,REG_CurrentNursery)
 354 #else
 355 #define CurrentNursery (BaseReg->rCurrentNursery)
 356 #endif
 357
 358 #if defined(REG_HpAlloc) && !defined(NO_GLOBAL_REG_DECLS)
 359 GLOBAL_REG_DECL(bdescr *,HpAlloc,REG_HpAlloc)
 360 #else
 361 #define HpAlloc (BaseReg->rHpAlloc)
 362 #endif
 363
 364 /* -----------------------------------------------------------------------------
 365    Get absolute function pointers from the register table, to save
 366    code space.  On x86,
 367
 368        jmp  *-12(%ebx)
 369
 370    is shorter than
 371
 372        jmp absolute_address
 373
 374    as long as the offset is within the range of a signed byte
 375    (-128..+127).  So we pick some common absolute_addresses and put
 376    them in the register table.  As a bonus, linking time should also
 377    be reduced.
 378
 379    Other possible candidates in order of importance:
 380
 381      stg_upd_frame_info
 382      stg_CAF_BLACKHOLE_info
 383      stg_IND_STATIC_info
 384
 385    anything else probably isn't worth the effort.
 386
 387    -------------------------------------------------------------------------- */
 388
 389
 390 #define FunReg ((StgFunTable *)((void *)BaseReg - STG_FIELD_OFFSET(struct PartCapability_, r)))
 391
 392 #define stg_EAGER_BLACKHOLE_info  (FunReg->stgEagerBlackholeInfo)
 393 #define stg_gc_enter_1            (FunReg->stgGCEnter1)
 394 #define stg_gc_fun                (FunReg->stgGCFun)
 395
 396 /* -----------------------------------------------------------------------------
 397    For any registers which are denoted "caller-saves" by the C calling
 398    convention, we have to emit code to save and restore them across C
 399    calls.
 400    -------------------------------------------------------------------------- */
 401
 402 #ifdef CALLER_SAVES_R1
 403 #define CALLER_SAVE_R1          SAVE_R1 = R1;
 404 #define CALLER_RESTORE_R1       R1 = SAVE_R1;
 405 #else
 406 #define CALLER_SAVE_R1          /* nothing */
 407 #define CALLER_RESTORE_R1       /* nothing */
 408 #endif
 409
 410 #ifdef CALLER_SAVES_R2
 411 #define CALLER_SAVE_R2          SAVE_R2 = R2;
 412 #define CALLER_RESTORE_R2       R2 = SAVE_R2;
 413 #else
 414 #define CALLER_SAVE_R2          /* nothing */
 415 #define CALLER_RESTORE_R2       /* nothing */
 416 #endif
 417
 418 #ifdef CALLER_SAVES_R3
 419 #define CALLER_SAVE_R3          SAVE_R3 = R3;
 420 #define CALLER_RESTORE_R3       R3 = SAVE_R3;
 421 #else
 422 #define CALLER_SAVE_R3          /* nothing */
 423 #define CALLER_RESTORE_R3       /* nothing */
 424 #endif
 425
 426 #ifdef CALLER_SAVES_R4
 427 #define CALLER_SAVE_R4          SAVE_R4 = R4;
 428 #define CALLER_RESTORE_R4       R4 = SAVE_R4;
 429 #else
 430 #define CALLER_SAVE_R4          /* nothing */
 431 #define CALLER_RESTORE_R4       /* nothing */
 432 #endif
 433
 434 #ifdef CALLER_SAVES_R5
 435 #define CALLER_SAVE_R5          SAVE_R5 = R5;
 436 #define CALLER_RESTORE_R5       R5 = SAVE_R5;
 437 #else
 438 #define CALLER_SAVE_R5          /* nothing */
 439 #define CALLER_RESTORE_R5       /* nothing */
 440 #endif
 441
 442 #ifdef CALLER_SAVES_R6
 443 #define CALLER_SAVE_R6          SAVE_R6 = R6;
 444 #define CALLER_RESTORE_R6       R6 = SAVE_R6;
 445 #else
 446 #define CALLER_SAVE_R6          /* nothing */
 447 #define CALLER_RESTORE_R6       /* nothing */
 448 #endif
 449
 450 #ifdef CALLER_SAVES_R7
 451 #define CALLER_SAVE_R7          SAVE_R7 = R7;
 452 #define CALLER_RESTORE_R7       R7 = SAVE_R7;
 453 #else
 454 #define CALLER_SAVE_R7          /* nothing */
 455 #define CALLER_RESTORE_R7       /* nothing */
 456 #endif
 457
 458 #ifdef CALLER_SAVES_R8
 459 #define CALLER_SAVE_R8          SAVE_R8 = R8;
 460 #define CALLER_RESTORE_R8       R8 = SAVE_R8;
 461 #else
 462 #define CALLER_SAVE_R8          /* nothing */
 463 #define CALLER_RESTORE_R8       /* nothing */
 464 #endif
 465
 466 #ifdef CALLER_SAVES_R9
 467 #define CALLER_SAVE_R9          SAVE_R9 = R9;
 468 #define CALLER_RESTORE_R9       R9 = SAVE_R9;
 469 #else
 470 #define CALLER_SAVE_R9          /* nothing */
 471 #define CALLER_RESTORE_R9       /* nothing */
 472 #endif
 473
 474 #ifdef CALLER_SAVES_R10
 475 #define CALLER_SAVE_R10         SAVE_R10 = R10;
 476 #define CALLER_RESTORE_R10      R10 = SAVE_R10;
 477 #else
 478 #define CALLER_SAVE_R10         /* nothing */
 479 #define CALLER_RESTORE_R10      /* nothing */
 480 #endif
 481
 482 #ifdef CALLER_SAVES_F1
 483 #define CALLER_SAVE_F1          SAVE_F1 = F1;
 484 #define CALLER_RESTORE_F1       F1 = SAVE_F1;
 485 #else
 486 #define CALLER_SAVE_F1          /* nothing */
 487 #define CALLER_RESTORE_F1       /* nothing */
 488 #endif
 489
 490 #ifdef CALLER_SAVES_F2
 491 #define CALLER_SAVE_F2          SAVE_F2 = F2;
 492 #define CALLER_RESTORE_F2       F2 = SAVE_F2;
 493 #else
 494 #define CALLER_SAVE_F2          /* nothing */
 495 #define CALLER_RESTORE_F2       /* nothing */
 496 #endif
 497
 498 #ifdef CALLER_SAVES_F3
 499 #define CALLER_SAVE_F3          SAVE_F3 = F3;
 500 #define CALLER_RESTORE_F3       F3 = SAVE_F3;
 501 #else
 502 #define CALLER_SAVE_F3          /* nothing */
 503 #define CALLER_RESTORE_F3       /* nothing */
 504 #endif
 505
 506 #ifdef CALLER_SAVES_F4
 507 #define CALLER_SAVE_F4          SAVE_F4 = F4;
 508 #define CALLER_RESTORE_F4       F4 = SAVE_F4;
 509 #else
 510 #define CALLER_SAVE_F4          /* nothing */
 511 #define CALLER_RESTORE_F4       /* nothing */
 512 #endif
 513
 514 #ifdef CALLER_SAVES_D1
 515 #define CALLER_SAVE_D1          SAVE_D1 = D1;
 516 #define CALLER_RESTORE_D1       D1 = SAVE_D1;
 517 #else
 518 #define CALLER_SAVE_D1          /* nothing */
 519 #define CALLER_RESTORE_D1       /* nothing */
 520 #endif
 521
 522 #ifdef CALLER_SAVES_D2
 523 #define CALLER_SAVE_D2          SAVE_D2 = D2;
 524 #define CALLER_RESTORE_D2       D2 = SAVE_D2;
 525 #else
 526 #define CALLER_SAVE_D2          /* nothing */
 527 #define CALLER_RESTORE_D2       /* nothing */
 528 #endif
 529
 530 #ifdef CALLER_SAVES_L1
 531 #define CALLER_SAVE_L1          SAVE_L1 = L1;
 532 #define CALLER_RESTORE_L1       L1 = SAVE_L1;
 533 #else
 534 #define CALLER_SAVE_L1          /* nothing */
 535 #define CALLER_RESTORE_L1       /* nothing */
 536 #endif
 537
 538 #ifdef CALLER_SAVES_Sp
 539 #define CALLER_SAVE_Sp          SAVE_Sp = Sp;
 540 #define CALLER_RESTORE_Sp       Sp = SAVE_Sp;
 541 #else
 542 #define CALLER_SAVE_Sp          /* nothing */
 543 #define CALLER_RESTORE_Sp       /* nothing */
 544 #endif
 545
 546 #ifdef CALLER_SAVES_SpLim
 547 #define CALLER_SAVE_SpLim       SAVE_SpLim = SpLim;
 548 #define CALLER_RESTORE_SpLim    SpLim = SAVE_SpLim;
 549 #else
 550 #define CALLER_SAVE_SpLim       /* nothing */
 551 #define CALLER_RESTORE_SpLim    /* nothing */
 552 #endif
 553
 554 #ifdef CALLER_SAVES_Hp
 555 #define CALLER_SAVE_Hp          SAVE_Hp = Hp;
 556 #define CALLER_RESTORE_Hp       Hp = SAVE_Hp;
 557 #else
 558 #define CALLER_SAVE_Hp          /* nothing */
 559 #define CALLER_RESTORE_Hp       /* nothing */
 560 #endif
 561
 562 #ifdef CALLER_SAVES_Base
 563 #ifdef THREADED_RTS
 564 #error "Can't have caller-saved BaseReg with THREADED_RTS"
 565 #endif
 566 #define CALLER_SAVE_Base        /* nothing */
 567 #define CALLER_RESTORE_Base     BaseReg = &MainRegTable;
 568 #else
 569 #define CALLER_SAVE_Base        /* nothing */
 570 #define CALLER_RESTORE_Base     /* nothing */
 571 #endif
 572
 573 #ifdef CALLER_SAVES_CurrentTSO
 574 #define CALLER_SAVE_CurrentTSO          SAVE_CurrentTSO = CurrentTSO;
 575 #define CALLER_RESTORE_CurrentTSO       CurrentTSO = SAVE_CurrentTSO;
 576 #else
 577 #define CALLER_SAVE_CurrentTSO          /* nothing */
 578 #define CALLER_RESTORE_CurrentTSO       /* nothing */
 579 #endif
 580
 581 #ifdef CALLER_SAVES_CurrentNursery
 582 #define CALLER_SAVE_CurrentNursery      SAVE_CurrentNursery = CurrentNursery;
 583 #define CALLER_RESTORE_CurrentNursery   CurrentNursery = SAVE_CurrentNursery;
 584 #else
 585 #define CALLER_SAVE_CurrentNursery      /* nothing */
 586 #define CALLER_RESTORE_CurrentNursery   /* nothing */
 587 #endif
 588
 589 #ifdef CALLER_SAVES_HpAlloc
 590 #define CALLER_SAVE_HpAlloc             SAVE_HpAlloc = HpAlloc;
 591 #define CALLER_RESTORE_HpAlloc          HpAlloc = SAVE_HpAlloc;
 592 #else
 593 #define CALLER_SAVE_HpAlloc             /* nothing */
 594 #define CALLER_RESTORE_HpAlloc          /* nothing */
 595 #endif
 596
 597 #endif /* IN_STG_CODE */
 598
 599 /* ----------------------------------------------------------------------------
 600    Handy bunches of saves/restores
 601    ------------------------------------------------------------------------  */
 602
 603 #if IN_STG_CODE
 604
 605 #define CALLER_SAVE_USER                        \
 606   CALLER_SAVE_R1                                \
 607   CALLER_SAVE_R2                                \
 608   CALLER_SAVE_R3                                \
 609   CALLER_SAVE_R4                                \
 610   CALLER_SAVE_R5                                \
 611   CALLER_SAVE_R6                                \
 612   CALLER_SAVE_R7                                \
 613   CALLER_SAVE_R8                                \
 614   CALLER_SAVE_F1                                \
 615   CALLER_SAVE_F2                                \
 616   CALLER_SAVE_F3                                \
 617   CALLER_SAVE_F4                                \
 618   CALLER_SAVE_D1                                \
 619   CALLER_SAVE_D2                                \
 620   CALLER_SAVE_L1
 621
 622      /* Save Base last, since the others may
 623         be addressed relative to it */
 624 #define CALLER_SAVE_SYSTEM                      \
 625   CALLER_SAVE_Sp                                \
 626   CALLER_SAVE_SpLim                             \
 627   CALLER_SAVE_Hp                                \
 628   CALLER_SAVE_CurrentTSO                        \
 629   CALLER_SAVE_CurrentNursery                    \
 630   CALLER_SAVE_Base
 631
 632 #define CALLER_RESTORE_USER                     \
 633   CALLER_RESTORE_R1                             \
 634   CALLER_RESTORE_R2                             \
 635   CALLER_RESTORE_R3                             \
 636   CALLER_RESTORE_R4                             \
 637   CALLER_RESTORE_R5                             \
 638   CALLER_RESTORE_R6                             \
 639   CALLER_RESTORE_R7                             \
 640   CALLER_RESTORE_R8                             \
 641   CALLER_RESTORE_F1                             \
 642   CALLER_RESTORE_F2                             \
 643   CALLER_RESTORE_F3                             \
 644   CALLER_RESTORE_F4                             \
 645   CALLER_RESTORE_D1                             \
 646   CALLER_RESTORE_D2                             \
 647   CALLER_RESTORE_L1
 648
 649      /* Restore Base first, since the others may
 650         be addressed relative to it */
 651 #define CALLER_RESTORE_SYSTEM                   \
 652   CALLER_RESTORE_Base                           \
 653   CALLER_RESTORE_Sp                             \
 654   CALLER_RESTORE_SpLim                          \
 655   CALLER_RESTORE_Hp                             \
 656   CALLER_RESTORE_CurrentTSO                     \
 657   CALLER_RESTORE_CurrentNursery
 658
 659 #else /* not IN_STG_CODE */
 660
 661 #define CALLER_SAVE_USER       /* nothing */
 662 #define CALLER_SAVE_SYSTEM     /* nothing */
 663 #define CALLER_RESTORE_USER    /* nothing */
 664 #define CALLER_RESTORE_SYSTEM  /* nothing */
 665
 666 #endif /* IN_STG_CODE */
 667 #define CALLER_SAVE_ALL                         \
 668   CALLER_SAVE_SYSTEM                            \
 669   CALLER_SAVE_USER
 670
 671 #define CALLER_RESTORE_ALL                      \
 672   CALLER_RESTORE_SYSTEM                         \
 673   CALLER_RESTORE_USER
 674
 675 #endif /* REGS_H */