ghc/includes/Regs.h

   1 /* -----------------------------------------------------------------------------
   2  * $Id: Regs.h,v 1.5 1999/11/02 15:05:51 simonmar Exp $
   3  *
   4  * (c) The GHC Team, 1998-1999
   5  *
   6  * Registers used in STG code.  Might or might not correspond to
   7  * actual machine registers.
   8  *
   9  * ---------------------------------------------------------------------------*/
  10
  11 #ifndef REGS_H
  12 #define REGS_H
  13
  14 /*
  15  * This file should do the right thing if we have no machine-registers
  16  * defined, i.e. everything lives in the RegTable.
  17  */
  18
  19 /*
  20  * This is the table that holds shadow-locations for all the STG
  21  * registers.  The shadow locations are used when:
  22  *
  23  *     1) the particular register isn't mapped to a real machine
  24  *        register, probably because there's a shortage of real registers.
  25  *     2) caller-saves registers are saved across a CCall
  26  */
  27
  28 typedef struct StgRegTable_ {
  29   StgUnion        rR1;
  30   StgUnion        rR2;
  31   StgUnion        rR3;
  32   StgUnion        rR4;
  33   StgUnion        rR5;
  34   StgUnion        rR6;
  35   StgUnion        rR7;
  36   StgUnion        rR8;
  37   StgUnion        rR9;          /* used occasionally by heap/stack checks */
  38   StgUnion        rR10;         /* used occasionally by heap/stack checks */
  39   StgFloat        rF1;
  40   StgFloat        rF2;
  41   StgFloat        rF3;
  42   StgFloat        rF4;
  43   StgDouble       rD1;
  44   StgDouble       rD2;
  45   StgWord64       rL1;
  46   StgPtr          rSp;
  47   StgUpdateFrame *rSu;
  48   StgPtr          rSpLim;
  49   StgPtr          rHp;
  50   StgPtr          rHpLim;
  51   StgTSO         *rCurrentTSO;
  52   bdescr         *rNursery;
  53   bdescr         *rCurrentNursery;
  54 #ifdef SMP
  55   struct StgRegTable_ *link;
  56 #endif
  57 } StgRegTable;
  58
  59 /* No such thing as a MainRegTable under SMP - each thread must
  60  * have its own MainRegTable.
  61  */
  62 #ifndef SMP
  63 extern DLL_IMPORT_RTS StgRegTable  MainRegTable;
  64 #endif
  65
  66 #ifdef IN_STG_CODE
  67
  68 /*
  69  * Registers Hp and HpLim are global across the entire system, and are
  70  * copied into the RegTable before executing a thread.
  71  *
  72  * Registers Sp, Su, and SpLim are saved in the TSO for the
  73  * thread, but are copied into the RegTable before executing a thread.
  74  *
  75  * All other registers are "general purpose", and are used for passing
  76  * arguments to functions, and returning values.  The code generator
  77  * knows how many of these are in real registers, and avoids
  78  * generating code that uses non-real registers.  General purpose
  79  * registers are never saved when returning to the scheduler, instead
  80  * we save whatever is live at the time on the stack, and restore it
  81  * later.  This should reduce the context switch time, amongst other
  82  * things.
  83  *
  84  * For argument passing, the stack will be used in preference to
  85  * pseudo-registers if the architecture has too few general purpose
  86  * registers.
  87  *
  88  * Some special RTS functions like newArray and the Integer primitives
  89  * expect their arguments to be in registers R1-Rn, so we use these
  90  * (pseudo-)registers in those cases.
  91  */
  92
  93 /*
  94  * Locations for saving per-thread registers.
  95  */
  96
  97 #define SAVE_Sp             (CurrentTSO->sp)
  98 #define SAVE_Su             (CurrentTSO->su)
  99 #define SAVE_SpLim          (CurrentTSO->splim)
 100
 101 #define SAVE_Hp             (BaseReg->rHp)
 102 #define SAVE_HpLim          (BaseReg->rHpLim)
 103
 104 #define SAVE_CurrentTSO     (BaseReg->rCurrentTSO)
 105 #define SAVE_CurrentNursery (BaseReg->rCurrentNursery)
 106
 107 /* We sometimes need to save registers across a C-call, eg. if they
 108  * are clobbered in the standard calling convention.  We define the
 109  * save locations for all registers in the register table.
 110  */
 111
 112 #define SAVE_R1             (BaseReg->rR1)
 113 #define SAVE_R2             (BaseReg->rR2)
 114 #define SAVE_R3             (BaseReg->rR3)
 115 #define SAVE_R4             (BaseReg->rR4)
 116 #define SAVE_R5             (BaseReg->rR5)
 117 #define SAVE_R6             (BaseReg->rR6)
 118 #define SAVE_R7             (BaseReg->rR7)
 119 #define SAVE_R8             (BaseReg->rR8)
 120
 121 #define SAVE_F1             (BaseReg->rF1)
 122 #define SAVE_F2             (BaseReg->rF2)
 123 #define SAVE_F3             (BaseReg->rF3)
 124 #define SAVE_F4             (BaseReg->rF4)
 125
 126 #define SAVE_D1             (BaseReg->rD1)
 127 #define SAVE_D2             (BaseReg->rD2)
 128
 129 #define SAVE_L1             (BaseReg->rL1)
 130
 131 /* -----------------------------------------------------------------------------
 132  * Emit the GCC-specific register declarations for each machine
 133  * register being used.  If any STG register isn't mapped to a machine
 134  * register, then map it to an offset from BaseReg.
 135  *
 136  * First, the general purpose registers.  The idea is, if a particular
 137  * general-purpose STG register can't be mapped to a real machine
 138  * register, it won't be used at all.  Instead, we'll use the stack.
 139  *
 140  * This is an improvement on the way things used to be done, when all
 141  * registers were mapped to locations in the register table, and stuff
 142  * was being shifted from the stack to the register table and back
 143  * again for no good reason (on register-poor architectures).
 144  */
 145
 146 #define GLOBAL_REG_DECL(type,name,reg) register type name REG(reg);
 147
 148 #ifdef REG_R1
 149 GLOBAL_REG_DECL(StgUnion,R1,REG_R1)
 150 #else
 151 #define R1 (BaseReg->rR1)
 152 #endif
 153
 154 #ifdef REG_R2
 155 GLOBAL_REG_DECL(StgUnion,R2,REG_R2)
 156 #else
 157 #define R2 (BaseReg->rR2)
 158 #endif
 159
 160 #ifdef REG_R3
 161 GLOBAL_REG_DECL(StgUnion,R3,REG_R3)
 162 #else
 163 # define R3 (BaseReg->rR3)
 164 #endif
 165
 166 #ifdef REG_R4
 167 GLOBAL_REG_DECL(StgUnion,R4,REG_R4)
 168 #else
 169 # define R4 (BaseReg->rR4)
 170 #endif
 171
 172 #ifdef REG_R5
 173 GLOBAL_REG_DECL(StgUnion,R5,REG_R5)
 174 #else
 175 # define R5 (BaseReg->rR5)
 176 #endif
 177
 178 #ifdef REG_R6
 179 GLOBAL_REG_DECL(StgUnion,R6,REG_R6)
 180 #else
 181 # define R6 (BaseReg->rR6)
 182 #endif
 183
 184 #ifdef REG_R7
 185 GLOBAL_REG_DECL(StgUnion,R7,REG_R7)
 186 #else
 187 # define R7 (BaseReg->rR7)
 188 #endif
 189
 190 #ifdef REG_R8
 191 GLOBAL_REG_DECL(StgUnion,R8,REG_R8)
 192 #else
 193 # define R8 (BaseReg->rR8)
 194 #endif
 195
 196 #ifdef REG_R9
 197 GLOBAL_REG_DECL(StgUnion,R9,REG_R9)
 198 #else
 199 # define R9 (BaseReg->rR9)
 200 #endif
 201
 202 #ifdef REG_R10
 203 GLOBAL_REG_DECL(StgUnion,R10,REG_R10)
 204 #else
 205 # define R10 (BaseReg->rR10)
 206 #endif
 207
 208 #ifdef REG_F1
 209 GLOBAL_REG_DECL(StgFloat,F1,REG_F1)
 210 #else
 211 #define F1 (BaseReg->rF1)
 212 #endif
 213
 214 #ifdef REG_F2
 215 GLOBAL_REG_DECL(StgFloat,F2,REG_F2)
 216 #else
 217 #define F2 (BaseReg->rF2)
 218 #endif
 219
 220 #ifdef REG_F3
 221 GLOBAL_REG_DECL(StgFloat,F3,REG_F3)
 222 #else
 223 #define F3 (BaseReg->rF3)
 224 #endif
 225
 226 #ifdef REG_F4
 227 GLOBAL_REG_DECL(StgFloat,F4,REG_F4)
 228 #else
 229 #define F4 (BaseReg->rF4)
 230 #endif
 231
 232 #ifdef REG_D1
 233 GLOBAL_REG_DECL(StgDouble,D1,REG_D1)
 234 #else
 235 #define D1 (BaseReg->rD1)
 236 #endif
 237
 238 #ifdef REG_D2
 239 GLOBAL_REG_DECL(StgDouble,D2,REG_D2)
 240 #else
 241 #define D2 (BaseReg->rD2)
 242 #endif
 243
 244 #ifdef REG_L1
 245 GLOBAL_REG_DECL(StgWord64,L1,REG_L1)
 246 #else
 247 #define L1 (BaseReg->rL1)
 248 #endif
 249
 250 /*
 251  * If BaseReg isn't mapped to a machine register, just use the global
 252  * address of the current register table (CurrentRegTable in
 253  * concurrent Haskell, MainRegTable otherwise).
 254  */
 255
 256 #ifdef REG_Base
 257 GLOBAL_REG_DECL(StgRegTable *,BaseReg,REG_Base)
 258 #else
 259 #ifdef SMP
 260 #error BaseReg must be in a register for SMP
 261 #endif
 262 #define BaseReg (&MainRegTable)
 263 #endif
 264
 265 #ifdef REG_Sp
 266 GLOBAL_REG_DECL(P_,Sp,REG_Sp)
 267 #else
 268 #define Sp (BaseReg->rSp)
 269 #endif
 270
 271 #ifdef REG_Su
 272 GLOBAL_REG_DECL(StgUpdateFrame *,Su,REG_Su)
 273 #else
 274 #define Su (BaseReg->rSu)
 275 #endif
 276
 277 #ifdef REG_SpLim
 278 GLOBAL_REG_DECL(P_,SpLim,REG_SpLim)
 279 #else
 280 #define SpLim (BaseReg->rSpLim)
 281 #endif
 282
 283 #ifdef REG_Hp
 284 GLOBAL_REG_DECL(P_,Hp,REG_Hp)
 285 #else
 286 #define Hp (BaseReg->rHp)
 287 #endif
 288
 289 #ifdef REG_HpLim
 290 GLOBAL_REG_DECL(P_,HpLim,REG_HpLim)
 291 #else
 292 #define HpLim (BaseReg->rHpLim)
 293 #endif
 294
 295 #ifdef REG_CurrentTSO
 296 GLOBAL_REG_DECL(StgTSO *,CurrentTSO,REG_CurrentTSO)
 297 #else
 298 #define CurrentTSO (BaseReg->rCurrentTSO)
 299 #endif
 300
 301 #ifdef REG_CurrentNursery
 302 GLOBAL_REG_DECL(bdescr *,CurrentNursery,REG_CurrentNursery)
 303 #else
 304 #define CurrentNursery (BaseReg->rCurrentNursery)
 305 #endif
 306
 307 /* -----------------------------------------------------------------------------
 308    For any registers which are denoted "caller-saves" by the C calling
 309    convention, we have to emit code to save and restore them across C
 310    calls.
 311    -------------------------------------------------------------------------- */
 312
 313 #ifdef CALLER_SAVES_R1
 314 #define CALLER_SAVE_R1          SAVE_R1 = R1;
 315 #define CALLER_RESTORE_R1       R1 = SAVE_R1;
 316 #else
 317 #define CALLER_SAVE_R1          /* nothing */
 318 #define CALLER_RESTORE_R1       /* nothing */
 319 #endif
 320
 321 #ifdef CALLER_SAVES_R2
 322 #define CALLER_SAVE_R2          SAVE_R2 = R2;
 323 #define CALLER_RESTORE_R2       R2 = SAVE_R2;
 324 #else
 325 #define CALLER_SAVE_R2          /* nothing */
 326 #define CALLER_RESTORE_R2       /* nothing */
 327 #endif
 328
 329 #ifdef CALLER_SAVES_R3
 330 #define CALLER_SAVE_R3          SAVE_R3 = R3;
 331 #define CALLER_RESTORE_R3       R3 = SAVE_R3;
 332 #else
 333 #define CALLER_SAVE_R3          /* nothing */
 334 #define CALLER_RESTORE_R3       /* nothing */
 335 #endif
 336
 337 #ifdef CALLER_SAVES_R4
 338 #define CALLER_SAVE_R4          SAVE_R4 = R4;
 339 #define CALLER_RESTORE_R4       R4 = SAVE_R4;
 340 #else
 341 #define CALLER_SAVE_R4          /* nothing */
 342 #define CALLER_RESTORE_R4       /* nothing */
 343 #endif
 344
 345 #ifdef CALLER_SAVES_R5
 346 #define CALLER_SAVE_R5          SAVE_R5 = R5;
 347 #define CALLER_RESTORE_R5       R5 = SAVE_R5;
 348 #else
 349 #define CALLER_SAVE_R5          /* nothing */
 350 #define CALLER_RESTORE_R5       /* nothing */
 351 #endif
 352
 353 #ifdef CALLER_SAVES_R6
 354 #define CALLER_SAVE_R6          SAVE_R6 = R6;
 355 #define CALLER_RESTORE_R6       R6 = SAVE_R6;
 356 #else
 357 #define CALLER_SAVE_R6          /* nothing */
 358 #define CALLER_RESTORE_R6       /* nothing */
 359 #endif
 360
 361 #ifdef CALLER_SAVES_R7
 362 #define CALLER_SAVE_R7          SAVE_R7 = R7;
 363 #define CALLER_RESTORE_R7       R7 = SAVE_R7;
 364 #else
 365 #define CALLER_SAVE_R7          /* nothing */
 366 #define CALLER_RESTORE_R7       /* nothing */
 367 #endif
 368
 369 #ifdef CALLER_SAVES_R8
 370 #define CALLER_SAVE_R8          SAVE_R8 = R8;
 371 #define CALLER_RESTORE_R8       R8 = SAVE_R8;
 372 #else
 373 #define CALLER_SAVE_R8          /* nothing */
 374 #define CALLER_RESTORE_R8       /* nothing */
 375 #endif
 376
 377 #ifdef CALLER_SAVES_R9
 378 #define CALLER_SAVE_R9          SAVE_R9 = R9;
 379 #define CALLER_RESTORE_R9       R9 = SAVE_R9;
 380 #else
 381 #define CALLER_SAVE_R9          /* nothing */
 382 #define CALLER_RESTORE_R9       /* nothing */
 383 #endif
 384
 385 #ifdef CALLER_SAVES_R10
 386 #define CALLER_SAVE_R10         SAVE_R10 = R10;
 387 #define CALLER_RESTORE_R10      R10 = SAVE_R10;
 388 #else
 389 #define CALLER_SAVE_R10         /* nothing */
 390 #define CALLER_RESTORE_R10      /* nothing */
 391 #endif
 392
 393 #ifdef CALLER_SAVES_F1
 394 #define CALLER_SAVE_F1          SAVE_F1 = F1;
 395 #define CALLER_RESTORE_F1       F1 = SAVE_F1;
 396 #else
 397 #define CALLER_SAVE_F1          /* nothing */
 398 #define CALLER_RESTORE_F1       /* nothing */
 399 #endif
 400
 401 #ifdef CALLER_SAVES_F2
 402 #define CALLER_SAVE_F2          SAVE_F2 = F2;
 403 #define CALLER_RESTORE_F2       F2 = SAVE_F2;
 404 #else
 405 #define CALLER_SAVE_F2          /* nothing */
 406 #define CALLER_RESTORE_F2       /* nothing */
 407 #endif
 408
 409 #ifdef CALLER_SAVES_F3
 410 #define CALLER_SAVE_F3          SAVE_F3 = F3;
 411 #define CALLER_RESTORE_F3       F3 = SAVE_F3;
 412 #else
 413 #define CALLER_SAVE_F3          /* nothing */
 414 #define CALLER_RESTORE_F3       /* nothing */
 415 #endif
 416
 417 #ifdef CALLER_SAVES_F4
 418 #define CALLER_SAVE_F4          SAVE_F4 = F4;
 419 #define CALLER_RESTORE_F4       F4 = SAVE_F4;
 420 #else
 421 #define CALLER_SAVE_F4          /* nothing */
 422 #define CALLER_RESTORE_F4       /* nothing */
 423 #endif
 424
 425 #ifdef CALLER_SAVES_D1
 426 #define CALLER_SAVE_D1          SAVE_D1 = D1;
 427 #define CALLER_RESTORE_D1       D1 = SAVE_D1;
 428 #else
 429 #define CALLER_SAVE_D1          /* nothing */
 430 #define CALLER_RESTORE_D1       /* nothing */
 431 #endif
 432
 433 #ifdef CALLER_SAVES_D2
 434 #define CALLER_SAVE_D2          SAVE_D2 = D2;
 435 #define CALLER_RESTORE_D2       D2 = SAVE_D2;
 436 #else
 437 #define CALLER_SAVE_D2          /* nothing */
 438 #define CALLER_RESTORE_D2       /* nothing */
 439 #endif
 440
 441 #ifdef CALLER_SAVES_L1
 442 #define CALLER_SAVE_L1          SAVE_L1 = L1;
 443 #define CALLER_RESTORE_L1       L1 = SAVE_L1;
 444 #else
 445 #define CALLER_SAVE_L1          /* nothing */
 446 #define CALLER_RESTORE_L1       /* nothing */
 447 #endif
 448
 449 #ifdef CALLER_SAVES_Sp
 450 #define CALLER_SAVE_Sp          SAVE_Sp = Sp;
 451 #define CALLER_RESTORE_Sp       Sp = SAVE_Sp;
 452 #else
 453 #define CALLER_SAVE_Sp          /* nothing */
 454 #define CALLER_RESTORE_Sp       /* nothing */
 455 #endif
 456
 457 #ifdef CALLER_SAVES_Su
 458 #define CALLER_SAVE_Su          SAVE_Su = Su;
 459 #define CALLER_RESTORE_Su       Su = SAVE_Su;
 460 #else
 461 #define CALLER_SAVE_Su          /* nothing */
 462 #define CALLER_RESTORE_Su       /* nothing */
 463 #endif
 464
 465 #ifdef CALLER_SAVES_SpLim
 466 #define CALLER_SAVE_SpLim       SAVE_SpLim = SpLim;
 467 #define CALLER_RESTORE_SpLim    SpLim = SAVE_SpLim;
 468 #else
 469 #define CALLER_SAVE_SpLim       /* nothing */
 470 #define CALLER_RESTORE_SpLim    /* nothing */
 471 #endif
 472
 473 #ifdef CALLER_SAVES_Hp
 474 #define CALLER_SAVE_Hp          SAVE_Hp = Hp;
 475 #define CALLER_RESTORE_Hp       Hp = SAVE_Hp;
 476 #else
 477 #define CALLER_SAVE_Hp          /* nothing */
 478 #define CALLER_RESTORE_Hp       /* nothing */
 479 #endif
 480
 481 #ifdef CALLER_SAVES_HpLim
 482 #define CALLER_SAVE_HpLim       SAVE_HpLim = HpLim;
 483 #define CALLER_RESTORE_HpLim    HpLim = SAVE_HpLim;
 484 #else
 485 #define CALLER_SAVE_HpLim       /* nothing */
 486 #define CALLER_RESTORE_HpLim    /* nothing */
 487 #endif
 488
 489 #ifdef CALLER_SAVES_Base
 490 #ifdef SMP
 491 #error "Can't have caller-saved BaseReg with SMP"
 492 #endif
 493 #define CALLER_SAVE_Base        /* nothing */
 494 #define CALLER_RESTORE_Base     BaseReg = &MainRegTable;
 495 #else
 496 #define CALLER_SAVE_Base        /* nothing */
 497 #define CALLER_RESTORE_Base     /* nothing */
 498 #endif
 499
 500 #ifdef CALLER_SAVES_CurrentTSO
 501 #define CALLER_SAVE_CurrentTSO          SAVE_CurrentTSO = CurrentTSO;
 502 #define CALLER_RESTORE_CurrentTSO       CurrentTSO = SAVE_CurrentTSO;
 503 #else
 504 #define CALLER_SAVE_CurrentTSO          /* nothing */
 505 #define CALLER_RESTORE_CurrentTSO       /* nothing */
 506 #endif
 507
 508 #ifdef CALLER_SAVES_CurrentNursery
 509 #define CALLER_SAVE_CurrentNursery      SAVE_CurrentNursery = CurrentNursery;
 510 #define CALLER_RESTORE_CurrentNursery   CurrentNursery = SAVE_CurrentNursery;
 511 #else
 512 #define CALLER_SAVE_CurrentNursery      /* nothing */
 513 #define CALLER_RESTORE_CurrentNursery   /* nothing */
 514 #endif
 515
 516 #endif /* IN_STG_CODE */
 517
 518 /* ----------------------------------------------------------------------------
 519    Handy bunches of saves/restores
 520    ------------------------------------------------------------------------  */
 521
 522 #ifdef IN_STG_CODE
 523
 524 #define CALLER_SAVE_USER                        \
 525   CALLER_SAVE_R1                                \
 526   CALLER_SAVE_R2                                \
 527   CALLER_SAVE_R3                                \
 528   CALLER_SAVE_R4                                \
 529   CALLER_SAVE_R5                                \
 530   CALLER_SAVE_R6                                \
 531   CALLER_SAVE_R7                                \
 532   CALLER_SAVE_R8                                \
 533   CALLER_SAVE_F1                                \
 534   CALLER_SAVE_F2                                \
 535   CALLER_SAVE_F3                                \
 536   CALLER_SAVE_F4                                \
 537   CALLER_SAVE_D1                                \
 538   CALLER_SAVE_D2                                \
 539   CALLER_SAVE_L1
 540
 541 #define CALLER_SAVE_SYSTEM                      \
 542   CALLER_SAVE_Sp                                \
 543   CALLER_SAVE_Su                                \
 544   CALLER_SAVE_SpLim                             \
 545   CALLER_SAVE_Hp                                \
 546   CALLER_SAVE_HpLim                             \
 547   CALLER_SAVE_CurrentTSO                        \
 548   CALLER_SAVE_CurrentNursery
 549
 550 #define CALLER_RESTORE_USER                     \
 551   CALLER_RESTORE_R1                             \
 552   CALLER_RESTORE_R2                             \
 553   CALLER_RESTORE_R3                             \
 554   CALLER_RESTORE_R4                             \
 555   CALLER_RESTORE_R5                             \
 556   CALLER_RESTORE_R6                             \
 557   CALLER_RESTORE_R7                             \
 558   CALLER_RESTORE_R8                             \
 559   CALLER_RESTORE_F1                             \
 560   CALLER_RESTORE_F2                             \
 561   CALLER_RESTORE_F3                             \
 562   CALLER_RESTORE_F4                             \
 563   CALLER_RESTORE_D1                             \
 564   CALLER_RESTORE_D2                             \
 565   CALLER_RESTORE_L1
 566
 567 #define CALLER_RESTORE_SYSTEM                   \
 568   CALLER_RESTORE_Base                           \
 569   CALLER_RESTORE_Sp                             \
 570   CALLER_RESTORE_Su                             \
 571   CALLER_RESTORE_SpLim                          \
 572   CALLER_RESTORE_Hp                             \
 573   CALLER_RESTORE_HpLim                          \
 574   CALLER_RESTORE_CurrentTSO                     \
 575   CALLER_RESTORE_CurrentNursery
 576
 577 #else /* not IN_STG_CODE */
 578
 579 #define CALLER_SAVE_USER       /* nothing */
 580 #define CALLER_SAVE_SYSTEM     /* nothing */
 581 #define CALLER_RESTORE_USER    /* nothing */
 582 #define CALLER_RESTORE_SYSTEM  /* nothing */
 583
 584 #endif /* IN_STG_CODE */
 585
 586 #define CALLER_SAVE_ALL                         \
 587   CALLER_SAVE_SYSTEM                            \
 588   CALLER_SAVE_USER
 589
 590 #define CALLER_RESTORE_ALL                      \
 591   CALLER_RESTORE_SYSTEM                         \
 592   CALLER_RESTORE_USER
 593
 594 #endif /* REGS_H */
 595