ghc/includes/Regs.h

   1 /* -----------------------------------------------------------------------------
   2  * $Id: Regs.h,v 1.2 1998/12/02 13:21:20 simonm Exp $
   3  *
   4  * Registers used in STG code.  Might or might not correspond to
   5  * actual machine registers.
   6  *
   7  * ---------------------------------------------------------------------------*/
   8
   9 #ifndef REGS_H
  10 #define REGS_H
  11
  12 /*
  13  * This file should do the right thing if we have no machine-registers
  14  * defined, i.e. everything lives in the RegTable.
  15  */
  16
  17 /*
  18  * This is the table that holds shadow-locations for all the STG
  19  * registers.  The shadow locations are used when:
  20  *
  21  *     1) the particular register isn't mapped to a real machine
  22  *        register, probably because there's a shortage of real registers.
  23  *     2) caller-saves registers are saved across a CCall
  24  */
  25
  26 typedef struct {
  27   StgUnion        rR1;
  28   StgUnion        rR2;
  29   StgUnion        rR3;
  30   StgUnion        rR4;
  31   StgUnion        rR5;
  32   StgUnion        rR6;
  33   StgUnion        rR7;
  34   StgUnion        rR8;
  35   StgUnion        rR9;          /* used occasionally by heap/stack checks */
  36   StgUnion        rR10;         /* used occasionally by heap/stack checks */
  37   StgFloat        rF1;
  38   StgFloat        rF2;
  39   StgFloat        rF3;
  40   StgFloat        rF4;
  41   StgDouble       rD1;
  42   StgDouble       rD2;
  43   StgNat64        rL1;
  44   StgPtr          rSp;
  45   StgUpdateFrame *rSu;
  46   StgPtr          rSpLim;
  47   StgPtr          rHp;
  48   StgPtr          rHpLim;
  49 } StgRegTable;
  50
  51 extern StgRegTable  MainRegTable;
  52
  53 /*
  54  * Registers Hp and HpLim are global across the entire system, and are
  55  * copied into the RegTable before executing a thread.
  56  *
  57  * Registers Sp, Su, and SpLim are saved in the TSO for the
  58  * thread, but are copied into the RegTable before executing a thread.
  59  *
  60  * All other registers are "general purpose", and are used for passing
  61  * arguments to functions, and returning values.  The code generator
  62  * knows how many of these are in real registers, and avoids
  63  * generating code that uses non-real registers.  General purpose
  64  * registers are never saved when returning to the scheduler, instead
  65  * we save whatever is live at the time on the stack, and restore it
  66  * later.  This should reduce the context switch time, amongst other
  67  * things.
  68  *
  69  * For argument passing, the stack will be used in preference to
  70  * pseudo-registers if the architecture has too few general purpose
  71  * registers.
  72  *
  73  * Some special RTS functions like newArray and the Integer primitives
  74  * expect their arguments to be in registers R1-Rn, so we use these
  75  * (pseudo-)registers in those cases.
  76  */
  77
  78 /*
  79  * Locations for saving per-thread registers.
  80  */
  81
  82 #define SAVE_Sp             (CurrentTSO->sp)
  83 #define SAVE_Su             (CurrentTSO->su)
  84 #define SAVE_SpLim          (CurrentTSO->splim)
  85
  86 #define SAVE_Hp             (MainRegTable.rHp)
  87 #define SAVE_HpLim          (MainRegTable.rHpLim)
  88
  89 /* We sometimes need to save registers across a C-call, eg. if they
  90  * are clobbered in the standard calling convention.  We define the
  91  * save locations for all registers in the register table.
  92  */
  93
  94 #define SAVE_R1             (MainRegTable.rR1)
  95 #define SAVE_R2             (MainRegTable.rR2)
  96 #define SAVE_R3             (MainRegTable.rR3)
  97 #define SAVE_R4             (MainRegTable.rR4)
  98 #define SAVE_R5             (MainRegTable.rR5)
  99 #define SAVE_R6             (MainRegTable.rR6)
 100 #define SAVE_R7             (MainRegTable.rR7)
 101 #define SAVE_R8             (MainRegTable.rR8)
 102
 103 #define SAVE_F1             (MainRegTable.rF1)
 104 #define SAVE_F2             (MainRegTable.rF2)
 105 #define SAVE_F3             (MainRegTable.rF3)
 106 #define SAVE_F4             (MainRegTable.rF4)
 107
 108 #define SAVE_D1             (MainRegTable.rD1)
 109 #define SAVE_D2             (MainRegTable.rD2)
 110
 111 #define SAVE_L1             (MainRegTable.rL1)
 112
 113 /* -----------------------------------------------------------------------------
 114  * Emit the GCC-specific register declarations for each machine
 115  * register being used.  If any STG register isn't mapped to a machine
 116  * register, then map it to an offset from BaseReg.
 117  *
 118  * First, the general purpose registers.  The idea is, if a particular
 119  * general-purpose STG register can't be mapped to a real machine
 120  * register, it won't be used at all.  Instead, we'll use the stack.
 121  *
 122  * This is an improvement on the way things used to be done, when all
 123  * registers were mapped to locations in the register table, and stuff
 124  * was being shifted from the stack to the register table and back
 125  * again for no good reason (on register-poor architectures).
 126  */
 127
 128 #define GLOBAL_REG_DECL(type,name,reg) register type name REG(reg);
 129
 130 #ifdef REG_R1
 131 GLOBAL_REG_DECL(StgUnion,R1,REG_R1)
 132 #else
 133 #define R1 (BaseReg->rR1)
 134 #endif
 135
 136 #ifdef REG_R2
 137 GLOBAL_REG_DECL(StgUnion,R2,REG_R2)
 138 #else
 139 #define R2 (BaseReg->rR2)
 140 #endif
 141
 142 #ifdef REG_R3
 143 GLOBAL_REG_DECL(StgUnion,R3,REG_R3)
 144 #else
 145 # define R3 (BaseReg->rR3)
 146 #endif
 147
 148 #ifdef REG_R4
 149 GLOBAL_REG_DECL(StgUnion,R4,REG_R4)
 150 #else
 151 # define R4 (BaseReg->rR4)
 152 #endif
 153
 154 #ifdef REG_R5
 155 GLOBAL_REG_DECL(StgUnion,R5,REG_R5)
 156 #else
 157 # define R5 (BaseReg->rR5)
 158 #endif
 159
 160 #ifdef REG_R6
 161 GLOBAL_REG_DECL(StgUnion,R6,REG_R6)
 162 #else
 163 # define R6 (BaseReg->rR6)
 164 #endif
 165
 166 #ifdef REG_R7
 167 GLOBAL_REG_DECL(StgUnion,R7,REG_R7)
 168 #else
 169 # define R7 (BaseReg->rR7)
 170 #endif
 171
 172 #ifdef REG_R8
 173 GLOBAL_REG_DECL(StgUnion,R8,REG_R8)
 174 #else
 175 # define R8 (BaseReg->rR8)
 176 #endif
 177
 178 #ifdef REG_R9
 179 GLOBAL_REG_DECL(StgUnion,R9,REG_R9)
 180 #else
 181 # define R9 (BaseReg->rR9)
 182 #endif
 183
 184 #ifdef REG_R10
 185 GLOBAL_REG_DECL(StgUnion,R10,REG_R10)
 186 #else
 187 # define R10 (BaseReg->rR10)
 188 #endif
 189
 190 #ifdef REG_F1
 191 GLOBAL_REG_DECL(StgFloat,F1,REG_F1)
 192 #else
 193 #define F1 (BaseReg->rF1)
 194 #endif
 195
 196 #ifdef REG_F2
 197 GLOBAL_REG_DECL(StgFloat,F2,REG_F2)
 198 #else
 199 #define F2 (BaseReg->rF2)
 200 #endif
 201
 202 #ifdef REG_F3
 203 GLOBAL_REG_DECL(StgFloat,F3,REG_F3)
 204 #else
 205 #define F3 (BaseReg->rF3)
 206 #endif
 207
 208 #ifdef REG_F4
 209 GLOBAL_REG_DECL(StgFloat,F4,REG_F4)
 210 #else
 211 #define F4 (BaseReg->rF4)
 212 #endif
 213
 214 #ifdef REG_D1
 215 GLOBAL_REG_DECL(StgDouble,D1,REG_D1)
 216 #else
 217 #define D1 (BaseReg->rD1)
 218 #endif
 219
 220 #ifdef REG_D2
 221 GLOBAL_REG_DECL(StgDouble,D2,REG_D2)
 222 #else
 223 #define D2 (BaseReg->rD2)
 224 #endif
 225
 226 #ifdef REG_L1
 227 GLOBAL_REG_DECL(StgNat64,L1,REG_L1)
 228 #else
 229 #define L1 (BaseReg->rL1)
 230 #endif
 231
 232 /*
 233  * If BaseReg isn't mapped to a machine register, just use the global
 234  * address of the current register table (CurrentRegTable in
 235  * concurrent Haskell, MainRegTable otherwise).
 236  */
 237
 238 #ifdef REG_Base
 239 GLOBAL_REG_DECL(StgRegTable *,BaseReg,REG_Base)
 240 #else
 241 #define BaseReg (&MainRegTable)
 242 #endif
 243
 244 #ifdef REG_Sp
 245 GLOBAL_REG_DECL(P_,Sp,REG_Sp)
 246 #else
 247 #define Sp (BaseReg->rSp)
 248 #endif
 249
 250 #ifdef REG_Su
 251 GLOBAL_REG_DECL(StgUpdateFrame *,Su,REG_Su)
 252 #else
 253 #define Su (BaseReg->rSu)
 254 #endif
 255
 256 #ifdef REG_SpLim
 257 GLOBAL_REG_DECL(P_,SpLim,REG_SpLim)
 258 #else
 259 #define SpLim (BaseReg->rSpLim)
 260 #endif
 261
 262 #ifdef REG_Hp
 263 GLOBAL_REG_DECL(P_,Hp,REG_Hp)
 264 #else
 265 #define Hp (BaseReg->rHp)
 266 #endif
 267
 268 #ifdef REG_HpLim
 269 GLOBAL_REG_DECL(P_,HpLim,REG_HpLim)
 270 #else
 271 #define HpLim (BaseReg->rHpLim)
 272 #endif
 273
 274 /* -----------------------------------------------------------------------------
 275    For any registers which are denoted "caller-saves" by the C calling
 276    convention, we have to emit code to save and restore them across C
 277    calls.
 278    -------------------------------------------------------------------------- */
 279
 280 #ifdef CALLER_SAVES_R1
 281 #define CALLER_SAVE_R1          SAVE_R1 = R1;
 282 #define CALLER_RESTORE_R1       R1 = SAVE_R1;
 283 #else
 284 #define CALLER_SAVE_R1          /* nothing */
 285 #define CALLER_RESTORE_R1       /* nothing */
 286 #endif
 287
 288 #ifdef CALLER_SAVES_R2
 289 #define CALLER_SAVE_R2          SAVE_R2 = R2;
 290 #define CALLER_RESTORE_R2       R2 = SAVE_R2;
 291 #else
 292 #define CALLER_SAVE_R2          /* nothing */
 293 #define CALLER_RESTORE_R2       /* nothing */
 294 #endif
 295
 296 #ifdef CALLER_SAVES_R3
 297 #define CALLER_SAVE_R3          SAVE_R3 = R3;
 298 #define CALLER_RESTORE_R3       R3 = SAVE_R3;
 299 #else
 300 #define CALLER_SAVE_R3          /* nothing */
 301 #define CALLER_RESTORE_R3       /* nothing */
 302 #endif
 303
 304 #ifdef CALLER_SAVES_R4
 305 #define CALLER_SAVE_R4          SAVE_R4 = R4;
 306 #define CALLER_RESTORE_R4       R4 = SAVE_R4;
 307 #else
 308 #define CALLER_SAVE_R4          /* nothing */
 309 #define CALLER_RESTORE_R4       /* nothing */
 310 #endif
 311
 312 #ifdef CALLER_SAVES_R5
 313 #define CALLER_SAVE_R5          SAVE_R5 = R5;
 314 #define CALLER_RESTORE_R5       R5 = SAVE_R5;
 315 #else
 316 #define CALLER_SAVE_R5          /* nothing */
 317 #define CALLER_RESTORE_R5       /* nothing */
 318 #endif
 319
 320 #ifdef CALLER_SAVES_R6
 321 #define CALLER_SAVE_R6          SAVE_R6 = R6;
 322 #define CALLER_RESTORE_R6       R6 = SAVE_R6;
 323 #else
 324 #define CALLER_SAVE_R6          /* nothing */
 325 #define CALLER_RESTORE_R6       /* nothing */
 326 #endif
 327
 328 #ifdef CALLER_SAVES_R7
 329 #define CALLER_SAVE_R7          SAVE_R7 = R7;
 330 #define CALLER_RESTORE_R7       R7 = SAVE_R7;
 331 #else
 332 #define CALLER_SAVE_R7          /* nothing */
 333 #define CALLER_RESTORE_R7       /* nothing */
 334 #endif
 335
 336 #ifdef CALLER_SAVES_R8
 337 #define CALLER_SAVE_R8          SAVE_R8 = R8;
 338 #define CALLER_RESTORE_R8       R8 = SAVE_R8;
 339 #else
 340 #define CALLER_SAVE_R8          /* nothing */
 341 #define CALLER_RESTORE_R8       /* nothing */
 342 #endif
 343
 344 #ifdef CALLER_SAVES_R9
 345 #define CALLER_SAVE_R9          SAVE_R9 = R9;
 346 #define CALLER_RESTORE_R9       R9 = SAVE_R9;
 347 #else
 348 #define CALLER_SAVE_R9          /* nothing */
 349 #define CALLER_RESTORE_R9       /* nothing */
 350 #endif
 351
 352 #ifdef CALLER_SAVES_R10
 353 #define CALLER_SAVE_R10         SAVE_R10 = R10;
 354 #define CALLER_RESTORE_R10      R10 = SAVE_R10;
 355 #else
 356 #define CALLER_SAVE_R10         /* nothing */
 357 #define CALLER_RESTORE_R10      /* nothing */
 358 #endif
 359
 360 #ifdef CALLER_SAVES_F1
 361 #define CALLER_SAVE_F1          SAVE_F1 = F1;
 362 #define CALLER_RESTORE_F1       F1 = SAVE_F1;
 363 #else
 364 #define CALLER_SAVE_F1          /* nothing */
 365 #define CALLER_RESTORE_F1       /* nothing */
 366 #endif
 367
 368 #ifdef CALLER_SAVES_F2
 369 #define CALLER_SAVE_F2          SAVE_F2 = F2;
 370 #define CALLER_RESTORE_F2       F2 = SAVE_F2;
 371 #else
 372 #define CALLER_SAVE_F2          /* nothing */
 373 #define CALLER_RESTORE_F2       /* nothing */
 374 #endif
 375
 376 #ifdef CALLER_SAVES_F3
 377 #define CALLER_SAVE_F3          SAVE_F3 = F3;
 378 #define CALLER_RESTORE_F3       F3 = SAVE_F3;
 379 #else
 380 #define CALLER_SAVE_F3          /* nothing */
 381 #define CALLER_RESTORE_F3       /* nothing */
 382 #endif
 383
 384 #ifdef CALLER_SAVES_F4
 385 #define CALLER_SAVE_F4          SAVE_F4 = F4;
 386 #define CALLER_RESTORE_F4       F4 = SAVE_F4;
 387 #else
 388 #define CALLER_SAVE_F4          /* nothing */
 389 #define CALLER_RESTORE_F4       /* nothing */
 390 #endif
 391
 392 #ifdef CALLER_SAVES_D1
 393 #define CALLER_SAVE_D1          SAVE_D1 = D1;
 394 #define CALLER_RESTORE_D1       D1 = SAVE_D1;
 395 #else
 396 #define CALLER_SAVE_D1          /* nothing */
 397 #define CALLER_RESTORE_D1       /* nothing */
 398 #endif
 399
 400 #ifdef CALLER_SAVES_D2
 401 #define CALLER_SAVE_D2          SAVE_D2 = D2;
 402 #define CALLER_RESTORE_D2       D2 = SAVE_D2;
 403 #else
 404 #define CALLER_SAVE_D2          /* nothing */
 405 #define CALLER_RESTORE_D2       /* nothing */
 406 #endif
 407
 408 #ifdef CALLER_SAVES_L1
 409 #define CALLER_SAVE_L1          SAVE_L1 = L1;
 410 #define CALLER_RESTORE_L1       L1 = SAVE_L1;
 411 #else
 412 #define CALLER_SAVE_L1          /* nothing */
 413 #define CALLER_RESTORE_L1       /* nothing */
 414 #endif
 415
 416 #ifdef CALLER_SAVES_Sp
 417 #define CALLER_SAVE_Sp          SAVE_Sp = Sp;
 418 #define CALLER_RESTORE_Sp       Sp = SAVE_Sp;
 419 #else
 420 #define CALLER_SAVE_Sp          /* nothing */
 421 #define CALLER_RESTORE_Sp       /* nothing */
 422 #endif
 423
 424 #ifdef CALLER_SAVES_Su
 425 #define CALLER_SAVE_Su          SAVE_Su = Su;
 426 #define CALLER_RESTORE_Su       Su = SAVE_Su;
 427 #else
 428 #define CALLER_SAVE_Su          /* nothing */
 429 #define CALLER_RESTORE_Su       /* nothing */
 430 #endif
 431
 432 #ifdef CALLER_SAVES_SpLim
 433 #define CALLER_SAVE_SpLim       SAVE_SpLim = SpLim;
 434 #define CALLER_RESTORE_SpLim    SpLim = SAVE_SpLim;
 435 #else
 436 #define CALLER_SAVE_SpLim       /* nothing */
 437 #define CALLER_RESTORE_SpLim    /* nothing */
 438 #endif
 439
 440 #ifdef CALLER_SAVES_Hp
 441 #define CALLER_SAVE_Hp          SAVE_Hp = Hp;
 442 #define CALLER_RESTORE_Hp       Hp = SAVE_Hp;
 443 #else
 444 #define CALLER_SAVE_Hp          /* nothing */
 445 #define CALLER_RESTORE_Hp       /* nothing */
 446 #endif
 447
 448 #ifdef CALLER_SAVES_HpLim
 449 #define CALLER_SAVE_HpLim       SAVE_HpLim = HpLim;
 450 #define CALLER_RESTORE_HpLim    HpLim = SAVE_HpLim;
 451 #else
 452 #define CALLER_SAVE_HpLim       /* nothing */
 453 #define CALLER_RESTORE_HpLim    /* nothing */
 454 #endif
 455
 456 #ifdef CALLER_SAVES_Base
 457 #define CALLER_SAVE_Base        /* nothing */
 458 #define CALLER_RESTORE_Base     BaseReg = &MainRegTable;
 459 #else
 460 #define CALLER_SAVE_Base        /* nothing */
 461 #define CALLER_RESTORE_Base     /* nothing */
 462 #endif
 463
 464 /* ----------------------------------------------------------------------------
 465    Handy bunches of saves/restores
 466    ------------------------------------------------------------------------  */
 467
 468 #define CALLER_SAVE_USER                        \
 469   CALLER_SAVE_R1                                \
 470   CALLER_SAVE_R2                                \
 471   CALLER_SAVE_R3                                \
 472   CALLER_SAVE_R4                                \
 473   CALLER_SAVE_R5                                \
 474   CALLER_SAVE_R6                                \
 475   CALLER_SAVE_R7                                \
 476   CALLER_SAVE_R8                                \
 477   CALLER_SAVE_F1                                \
 478   CALLER_SAVE_F2                                \
 479   CALLER_SAVE_F3                                \
 480   CALLER_SAVE_F4                                \
 481   CALLER_SAVE_D1                                \
 482   CALLER_SAVE_D2                                \
 483   CALLER_SAVE_L1
 484
 485 #define CALLER_SAVE_SYSTEM                      \
 486   CALLER_SAVE_Sp                                \
 487   CALLER_SAVE_Su                                \
 488   CALLER_SAVE_SpLim                             \
 489   CALLER_SAVE_Hp                                \
 490   CALLER_SAVE_HpLim
 491
 492 #define CALLER_RESTORE_USER                     \
 493   CALLER_RESTORE_R1                             \
 494   CALLER_RESTORE_R2                             \
 495   CALLER_RESTORE_R3                             \
 496   CALLER_RESTORE_R4                             \
 497   CALLER_RESTORE_R5                             \
 498   CALLER_RESTORE_R6                             \
 499   CALLER_RESTORE_R7                             \
 500   CALLER_RESTORE_R8                             \
 501   CALLER_RESTORE_F1                             \
 502   CALLER_RESTORE_F2                             \
 503   CALLER_RESTORE_F3                             \
 504   CALLER_RESTORE_F4                             \
 505   CALLER_RESTORE_D1                             \
 506   CALLER_RESTORE_D2                             \
 507   CALLER_RESTORE_L1
 508
 509 #define CALLER_RESTORE_SYSTEM                   \
 510   CALLER_RESTORE_Base                           \
 511   CALLER_RESTORE_Sp                             \
 512   CALLER_RESTORE_Su                             \
 513   CALLER_RESTORE_SpLim                          \
 514   CALLER_RESTORE_Hp                             \
 515   CALLER_RESTORE_HpLim
 516
 517 #define CALLER_SAVE_ALL                         \
 518   CALLER_SAVE_SYSTEM                            \
 519   CALLER_SAVE_USER
 520
 521 #define CALLER_RESTORE_ALL                      \
 522   CALLER_RESTORE_SYSTEM                         \
 523   CALLER_RESTORE_USER
 524
 525 #endif /* REGS_H */
 526