ghc/includes/Regs.h

   1 /* -----------------------------------------------------------------------------
   2  * $Id: Regs.h,v 1.3 1999/02/05 16:02:26 simonm 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 {
  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   StgNat64        rL1;
  46   StgPtr          rSp;
  47   StgUpdateFrame *rSu;
  48   StgPtr          rSpLim;
  49   StgPtr          rHp;
  50   StgPtr          rHpLim;
  51 } StgRegTable;
  52
  53 extern StgRegTable  MainRegTable;
  54
  55 /*
  56  * Registers Hp and HpLim are global across the entire system, and are
  57  * copied into the RegTable before executing a thread.
  58  *
  59  * Registers Sp, Su, and SpLim are saved in the TSO for the
  60  * thread, but are copied into the RegTable before executing a thread.
  61  *
  62  * All other registers are "general purpose", and are used for passing
  63  * arguments to functions, and returning values.  The code generator
  64  * knows how many of these are in real registers, and avoids
  65  * generating code that uses non-real registers.  General purpose
  66  * registers are never saved when returning to the scheduler, instead
  67  * we save whatever is live at the time on the stack, and restore it
  68  * later.  This should reduce the context switch time, amongst other
  69  * things.
  70  *
  71  * For argument passing, the stack will be used in preference to
  72  * pseudo-registers if the architecture has too few general purpose
  73  * registers.
  74  *
  75  * Some special RTS functions like newArray and the Integer primitives
  76  * expect their arguments to be in registers R1-Rn, so we use these
  77  * (pseudo-)registers in those cases.
  78  */
  79
  80 /*
  81  * Locations for saving per-thread registers.
  82  */
  83
  84 #define SAVE_Sp             (CurrentTSO->sp)
  85 #define SAVE_Su             (CurrentTSO->su)
  86 #define SAVE_SpLim          (CurrentTSO->splim)
  87
  88 #define SAVE_Hp             (MainRegTable.rHp)
  89 #define SAVE_HpLim          (MainRegTable.rHpLim)
  90
  91 /* We sometimes need to save registers across a C-call, eg. if they
  92  * are clobbered in the standard calling convention.  We define the
  93  * save locations for all registers in the register table.
  94  */
  95
  96 #define SAVE_R1             (MainRegTable.rR1)
  97 #define SAVE_R2             (MainRegTable.rR2)
  98 #define SAVE_R3             (MainRegTable.rR3)
  99 #define SAVE_R4             (MainRegTable.rR4)
 100 #define SAVE_R5             (MainRegTable.rR5)
 101 #define SAVE_R6             (MainRegTable.rR6)
 102 #define SAVE_R7             (MainRegTable.rR7)
 103 #define SAVE_R8             (MainRegTable.rR8)
 104
 105 #define SAVE_F1             (MainRegTable.rF1)
 106 #define SAVE_F2             (MainRegTable.rF2)
 107 #define SAVE_F3             (MainRegTable.rF3)
 108 #define SAVE_F4             (MainRegTable.rF4)
 109
 110 #define SAVE_D1             (MainRegTable.rD1)
 111 #define SAVE_D2             (MainRegTable.rD2)
 112
 113 #define SAVE_L1             (MainRegTable.rL1)
 114
 115 /* -----------------------------------------------------------------------------
 116  * Emit the GCC-specific register declarations for each machine
 117  * register being used.  If any STG register isn't mapped to a machine
 118  * register, then map it to an offset from BaseReg.
 119  *
 120  * First, the general purpose registers.  The idea is, if a particular
 121  * general-purpose STG register can't be mapped to a real machine
 122  * register, it won't be used at all.  Instead, we'll use the stack.
 123  *
 124  * This is an improvement on the way things used to be done, when all
 125  * registers were mapped to locations in the register table, and stuff
 126  * was being shifted from the stack to the register table and back
 127  * again for no good reason (on register-poor architectures).
 128  */
 129
 130 #define GLOBAL_REG_DECL(type,name,reg) register type name REG(reg);
 131
 132 #ifdef REG_R1
 133 GLOBAL_REG_DECL(StgUnion,R1,REG_R1)
 134 #else
 135 #define R1 (BaseReg->rR1)
 136 #endif
 137
 138 #ifdef REG_R2
 139 GLOBAL_REG_DECL(StgUnion,R2,REG_R2)
 140 #else
 141 #define R2 (BaseReg->rR2)
 142 #endif
 143
 144 #ifdef REG_R3
 145 GLOBAL_REG_DECL(StgUnion,R3,REG_R3)
 146 #else
 147 # define R3 (BaseReg->rR3)
 148 #endif
 149
 150 #ifdef REG_R4
 151 GLOBAL_REG_DECL(StgUnion,R4,REG_R4)
 152 #else
 153 # define R4 (BaseReg->rR4)
 154 #endif
 155
 156 #ifdef REG_R5
 157 GLOBAL_REG_DECL(StgUnion,R5,REG_R5)
 158 #else
 159 # define R5 (BaseReg->rR5)
 160 #endif
 161
 162 #ifdef REG_R6
 163 GLOBAL_REG_DECL(StgUnion,R6,REG_R6)
 164 #else
 165 # define R6 (BaseReg->rR6)
 166 #endif
 167
 168 #ifdef REG_R7
 169 GLOBAL_REG_DECL(StgUnion,R7,REG_R7)
 170 #else
 171 # define R7 (BaseReg->rR7)
 172 #endif
 173
 174 #ifdef REG_R8
 175 GLOBAL_REG_DECL(StgUnion,R8,REG_R8)
 176 #else
 177 # define R8 (BaseReg->rR8)
 178 #endif
 179
 180 #ifdef REG_R9
 181 GLOBAL_REG_DECL(StgUnion,R9,REG_R9)
 182 #else
 183 # define R9 (BaseReg->rR9)
 184 #endif
 185
 186 #ifdef REG_R10
 187 GLOBAL_REG_DECL(StgUnion,R10,REG_R10)
 188 #else
 189 # define R10 (BaseReg->rR10)
 190 #endif
 191
 192 #ifdef REG_F1
 193 GLOBAL_REG_DECL(StgFloat,F1,REG_F1)
 194 #else
 195 #define F1 (BaseReg->rF1)
 196 #endif
 197
 198 #ifdef REG_F2
 199 GLOBAL_REG_DECL(StgFloat,F2,REG_F2)
 200 #else
 201 #define F2 (BaseReg->rF2)
 202 #endif
 203
 204 #ifdef REG_F3
 205 GLOBAL_REG_DECL(StgFloat,F3,REG_F3)
 206 #else
 207 #define F3 (BaseReg->rF3)
 208 #endif
 209
 210 #ifdef REG_F4
 211 GLOBAL_REG_DECL(StgFloat,F4,REG_F4)
 212 #else
 213 #define F4 (BaseReg->rF4)
 214 #endif
 215
 216 #ifdef REG_D1
 217 GLOBAL_REG_DECL(StgDouble,D1,REG_D1)
 218 #else
 219 #define D1 (BaseReg->rD1)
 220 #endif
 221
 222 #ifdef REG_D2
 223 GLOBAL_REG_DECL(StgDouble,D2,REG_D2)
 224 #else
 225 #define D2 (BaseReg->rD2)
 226 #endif
 227
 228 #ifdef REG_L1
 229 GLOBAL_REG_DECL(StgNat64,L1,REG_L1)
 230 #else
 231 #define L1 (BaseReg->rL1)
 232 #endif
 233
 234 /*
 235  * If BaseReg isn't mapped to a machine register, just use the global
 236  * address of the current register table (CurrentRegTable in
 237  * concurrent Haskell, MainRegTable otherwise).
 238  */
 239
 240 #ifdef REG_Base
 241 GLOBAL_REG_DECL(StgRegTable *,BaseReg,REG_Base)
 242 #else
 243 #define BaseReg (&MainRegTable)
 244 #endif
 245
 246 #ifdef REG_Sp
 247 GLOBAL_REG_DECL(P_,Sp,REG_Sp)
 248 #else
 249 #define Sp (BaseReg->rSp)
 250 #endif
 251
 252 #ifdef REG_Su
 253 GLOBAL_REG_DECL(StgUpdateFrame *,Su,REG_Su)
 254 #else
 255 #define Su (BaseReg->rSu)
 256 #endif
 257
 258 #ifdef REG_SpLim
 259 GLOBAL_REG_DECL(P_,SpLim,REG_SpLim)
 260 #else
 261 #define SpLim (BaseReg->rSpLim)
 262 #endif
 263
 264 #ifdef REG_Hp
 265 GLOBAL_REG_DECL(P_,Hp,REG_Hp)
 266 #else
 267 #define Hp (BaseReg->rHp)
 268 #endif
 269
 270 #ifdef REG_HpLim
 271 GLOBAL_REG_DECL(P_,HpLim,REG_HpLim)
 272 #else
 273 #define HpLim (BaseReg->rHpLim)
 274 #endif
 275
 276 /* -----------------------------------------------------------------------------
 277    For any registers which are denoted "caller-saves" by the C calling
 278    convention, we have to emit code to save and restore them across C
 279    calls.
 280    -------------------------------------------------------------------------- */
 281
 282 #ifdef CALLER_SAVES_R1
 283 #define CALLER_SAVE_R1          SAVE_R1 = R1;
 284 #define CALLER_RESTORE_R1       R1 = SAVE_R1;
 285 #else
 286 #define CALLER_SAVE_R1          /* nothing */
 287 #define CALLER_RESTORE_R1       /* nothing */
 288 #endif
 289
 290 #ifdef CALLER_SAVES_R2
 291 #define CALLER_SAVE_R2          SAVE_R2 = R2;
 292 #define CALLER_RESTORE_R2       R2 = SAVE_R2;
 293 #else
 294 #define CALLER_SAVE_R2          /* nothing */
 295 #define CALLER_RESTORE_R2       /* nothing */
 296 #endif
 297
 298 #ifdef CALLER_SAVES_R3
 299 #define CALLER_SAVE_R3          SAVE_R3 = R3;
 300 #define CALLER_RESTORE_R3       R3 = SAVE_R3;
 301 #else
 302 #define CALLER_SAVE_R3          /* nothing */
 303 #define CALLER_RESTORE_R3       /* nothing */
 304 #endif
 305
 306 #ifdef CALLER_SAVES_R4
 307 #define CALLER_SAVE_R4          SAVE_R4 = R4;
 308 #define CALLER_RESTORE_R4       R4 = SAVE_R4;
 309 #else
 310 #define CALLER_SAVE_R4          /* nothing */
 311 #define CALLER_RESTORE_R4       /* nothing */
 312 #endif
 313
 314 #ifdef CALLER_SAVES_R5
 315 #define CALLER_SAVE_R5          SAVE_R5 = R5;
 316 #define CALLER_RESTORE_R5       R5 = SAVE_R5;
 317 #else
 318 #define CALLER_SAVE_R5          /* nothing */
 319 #define CALLER_RESTORE_R5       /* nothing */
 320 #endif
 321
 322 #ifdef CALLER_SAVES_R6
 323 #define CALLER_SAVE_R6          SAVE_R6 = R6;
 324 #define CALLER_RESTORE_R6       R6 = SAVE_R6;
 325 #else
 326 #define CALLER_SAVE_R6          /* nothing */
 327 #define CALLER_RESTORE_R6       /* nothing */
 328 #endif
 329
 330 #ifdef CALLER_SAVES_R7
 331 #define CALLER_SAVE_R7          SAVE_R7 = R7;
 332 #define CALLER_RESTORE_R7       R7 = SAVE_R7;
 333 #else
 334 #define CALLER_SAVE_R7          /* nothing */
 335 #define CALLER_RESTORE_R7       /* nothing */
 336 #endif
 337
 338 #ifdef CALLER_SAVES_R8
 339 #define CALLER_SAVE_R8          SAVE_R8 = R8;
 340 #define CALLER_RESTORE_R8       R8 = SAVE_R8;
 341 #else
 342 #define CALLER_SAVE_R8          /* nothing */
 343 #define CALLER_RESTORE_R8       /* nothing */
 344 #endif
 345
 346 #ifdef CALLER_SAVES_R9
 347 #define CALLER_SAVE_R9          SAVE_R9 = R9;
 348 #define CALLER_RESTORE_R9       R9 = SAVE_R9;
 349 #else
 350 #define CALLER_SAVE_R9          /* nothing */
 351 #define CALLER_RESTORE_R9       /* nothing */
 352 #endif
 353
 354 #ifdef CALLER_SAVES_R10
 355 #define CALLER_SAVE_R10         SAVE_R10 = R10;
 356 #define CALLER_RESTORE_R10      R10 = SAVE_R10;
 357 #else
 358 #define CALLER_SAVE_R10         /* nothing */
 359 #define CALLER_RESTORE_R10      /* nothing */
 360 #endif
 361
 362 #ifdef CALLER_SAVES_F1
 363 #define CALLER_SAVE_F1          SAVE_F1 = F1;
 364 #define CALLER_RESTORE_F1       F1 = SAVE_F1;
 365 #else
 366 #define CALLER_SAVE_F1          /* nothing */
 367 #define CALLER_RESTORE_F1       /* nothing */
 368 #endif
 369
 370 #ifdef CALLER_SAVES_F2
 371 #define CALLER_SAVE_F2          SAVE_F2 = F2;
 372 #define CALLER_RESTORE_F2       F2 = SAVE_F2;
 373 #else
 374 #define CALLER_SAVE_F2          /* nothing */
 375 #define CALLER_RESTORE_F2       /* nothing */
 376 #endif
 377
 378 #ifdef CALLER_SAVES_F3
 379 #define CALLER_SAVE_F3          SAVE_F3 = F3;
 380 #define CALLER_RESTORE_F3       F3 = SAVE_F3;
 381 #else
 382 #define CALLER_SAVE_F3          /* nothing */
 383 #define CALLER_RESTORE_F3       /* nothing */
 384 #endif
 385
 386 #ifdef CALLER_SAVES_F4
 387 #define CALLER_SAVE_F4          SAVE_F4 = F4;
 388 #define CALLER_RESTORE_F4       F4 = SAVE_F4;
 389 #else
 390 #define CALLER_SAVE_F4          /* nothing */
 391 #define CALLER_RESTORE_F4       /* nothing */
 392 #endif
 393
 394 #ifdef CALLER_SAVES_D1
 395 #define CALLER_SAVE_D1          SAVE_D1 = D1;
 396 #define CALLER_RESTORE_D1       D1 = SAVE_D1;
 397 #else
 398 #define CALLER_SAVE_D1          /* nothing */
 399 #define CALLER_RESTORE_D1       /* nothing */
 400 #endif
 401
 402 #ifdef CALLER_SAVES_D2
 403 #define CALLER_SAVE_D2          SAVE_D2 = D2;
 404 #define CALLER_RESTORE_D2       D2 = SAVE_D2;
 405 #else
 406 #define CALLER_SAVE_D2          /* nothing */
 407 #define CALLER_RESTORE_D2       /* nothing */
 408 #endif
 409
 410 #ifdef CALLER_SAVES_L1
 411 #define CALLER_SAVE_L1          SAVE_L1 = L1;
 412 #define CALLER_RESTORE_L1       L1 = SAVE_L1;
 413 #else
 414 #define CALLER_SAVE_L1          /* nothing */
 415 #define CALLER_RESTORE_L1       /* nothing */
 416 #endif
 417
 418 #ifdef CALLER_SAVES_Sp
 419 #define CALLER_SAVE_Sp          SAVE_Sp = Sp;
 420 #define CALLER_RESTORE_Sp       Sp = SAVE_Sp;
 421 #else
 422 #define CALLER_SAVE_Sp          /* nothing */
 423 #define CALLER_RESTORE_Sp       /* nothing */
 424 #endif
 425
 426 #ifdef CALLER_SAVES_Su
 427 #define CALLER_SAVE_Su          SAVE_Su = Su;
 428 #define CALLER_RESTORE_Su       Su = SAVE_Su;
 429 #else
 430 #define CALLER_SAVE_Su          /* nothing */
 431 #define CALLER_RESTORE_Su       /* nothing */
 432 #endif
 433
 434 #ifdef CALLER_SAVES_SpLim
 435 #define CALLER_SAVE_SpLim       SAVE_SpLim = SpLim;
 436 #define CALLER_RESTORE_SpLim    SpLim = SAVE_SpLim;
 437 #else
 438 #define CALLER_SAVE_SpLim       /* nothing */
 439 #define CALLER_RESTORE_SpLim    /* nothing */
 440 #endif
 441
 442 #ifdef CALLER_SAVES_Hp
 443 #define CALLER_SAVE_Hp          SAVE_Hp = Hp;
 444 #define CALLER_RESTORE_Hp       Hp = SAVE_Hp;
 445 #else
 446 #define CALLER_SAVE_Hp          /* nothing */
 447 #define CALLER_RESTORE_Hp       /* nothing */
 448 #endif
 449
 450 #ifdef CALLER_SAVES_HpLim
 451 #define CALLER_SAVE_HpLim       SAVE_HpLim = HpLim;
 452 #define CALLER_RESTORE_HpLim    HpLim = SAVE_HpLim;
 453 #else
 454 #define CALLER_SAVE_HpLim       /* nothing */
 455 #define CALLER_RESTORE_HpLim    /* nothing */
 456 #endif
 457
 458 #ifdef CALLER_SAVES_Base
 459 #define CALLER_SAVE_Base        /* nothing */
 460 #define CALLER_RESTORE_Base     BaseReg = &MainRegTable;
 461 #else
 462 #define CALLER_SAVE_Base        /* nothing */
 463 #define CALLER_RESTORE_Base     /* nothing */
 464 #endif
 465
 466 /* ----------------------------------------------------------------------------
 467    Handy bunches of saves/restores
 468    ------------------------------------------------------------------------  */
 469
 470 #define CALLER_SAVE_USER                        \
 471   CALLER_SAVE_R1                                \
 472   CALLER_SAVE_R2                                \
 473   CALLER_SAVE_R3                                \
 474   CALLER_SAVE_R4                                \
 475   CALLER_SAVE_R5                                \
 476   CALLER_SAVE_R6                                \
 477   CALLER_SAVE_R7                                \
 478   CALLER_SAVE_R8                                \
 479   CALLER_SAVE_F1                                \
 480   CALLER_SAVE_F2                                \
 481   CALLER_SAVE_F3                                \
 482   CALLER_SAVE_F4                                \
 483   CALLER_SAVE_D1                                \
 484   CALLER_SAVE_D2                                \
 485   CALLER_SAVE_L1
 486
 487 #define CALLER_SAVE_SYSTEM                      \
 488   CALLER_SAVE_Sp                                \
 489   CALLER_SAVE_Su                                \
 490   CALLER_SAVE_SpLim                             \
 491   CALLER_SAVE_Hp                                \
 492   CALLER_SAVE_HpLim
 493
 494 #define CALLER_RESTORE_USER                     \
 495   CALLER_RESTORE_R1                             \
 496   CALLER_RESTORE_R2                             \
 497   CALLER_RESTORE_R3                             \
 498   CALLER_RESTORE_R4                             \
 499   CALLER_RESTORE_R5                             \
 500   CALLER_RESTORE_R6                             \
 501   CALLER_RESTORE_R7                             \
 502   CALLER_RESTORE_R8                             \
 503   CALLER_RESTORE_F1                             \
 504   CALLER_RESTORE_F2                             \
 505   CALLER_RESTORE_F3                             \
 506   CALLER_RESTORE_F4                             \
 507   CALLER_RESTORE_D1                             \
 508   CALLER_RESTORE_D2                             \
 509   CALLER_RESTORE_L1
 510
 511 #define CALLER_RESTORE_SYSTEM                   \
 512   CALLER_RESTORE_Base                           \
 513   CALLER_RESTORE_Sp                             \
 514   CALLER_RESTORE_Su                             \
 515   CALLER_RESTORE_SpLim                          \
 516   CALLER_RESTORE_Hp                             \
 517   CALLER_RESTORE_HpLim
 518
 519 #define CALLER_SAVE_ALL                         \
 520   CALLER_SAVE_SYSTEM                            \
 521   CALLER_SAVE_USER
 522
 523 #define CALLER_RESTORE_ALL                      \
 524   CALLER_RESTORE_SYSTEM                         \
 525   CALLER_RESTORE_USER
 526
 527 #endif /* REGS_H */
 528