ghc/includes/Cmm.h

   1 /* -----------------------------------------------------------------------------
   2  *
   3  * (c) The University of Glasgow 2004
   4  *
   5  * This file is included at the top of all .cmm source files (and
   6  * *only* .cmm files).  It defines a collection of useful macros for
   7  * making .cmm code a bit less error-prone to write, and a bit easier
   8  * on the eye for the reader.
   9  *
  10  * For the syntax of .cmm files, see the parser in ghc/compiler/cmm/CmmParse.y.
  11  *
  12  * If you're used to the old HC file syntax, here's a quick cheat sheet
  13  * for converting HC code:
  14  *
  15  *       - Remove FB_/FE_
  16  *       - Remove all type casts
  17  *       - Remove '&'
  18  *       - STGFUN(foo) { ... }  ==>  foo { ... }
  19  *       - FN_(foo) { ... }  ==>  foo { ... }
  20  *       - JMP_(e)  ==> jump e;
  21  *       - Remove EXTFUN(foo)
  22  *       - Sp[n]  ==>  Sp(n)
  23  *       - Hp[n]  ==>  Hp(n)
  24  *       - Sp += n  ==> Sp_adj(n)
  25  *       - Hp += n  ==> Hp_adj(n)
  26  *       - R1.i   ==>  R1   (similarly for R1.w, R1.cl etc.)
  27  *       - You need to explicitly dereference variables; eg.
  28  *             context_switch   ==>  CInt[context_switch]
  29  *       - convert all word offsets into byte offsets:
  30  *              - e ==> WDS(e)
  31  *       - sizeofW(StgFoo)  ==>  SIZEOF_StgFoo
  32  *       - ENTRY_CODE(e)  ==>  %ENTRY_CODE(e)
  33  *       - get_itbl(c)  ==>  %GET_STD_INFO(c)
  34  *       - Change liveness masks in STK_CHK_GEN, HP_CHK_GEN:
  35  *              R1_PTR | R2_PTR  ==>  R1_PTR & R2_PTR
  36  *              (NOTE: | becomes &)
  37  *       - Declarations like 'StgPtr p;' become just 'W_ p;'
  38  *       - e->payload[n] ==> PAYLOAD(e,n)
  39  *       - Be very careful with comparisons: the infix versions (>, >=, etc.)
  40  *         are unsigned, so use %lt(a,b) to get signed less-than for example.
  41  *
  42  * Accessing fields of structures defined in the RTS header files is
  43  * done via automatically-generated macros in DerivedConstants.h.  For
  44  * example, where previously we used
  45  *
  46  *          CurrentTSO->what_next = x
  47  *
  48  * in C-- we now use
  49  *
  50  *          StgTSO_what_next(CurrentTSO) = x
  51  *
  52  * where the StgTSO_what_next() macro is automatically generated by
  53  * mkDerivedConstnants.c.  If you need to access a field that doesn't
  54  * already have a macro, edit that file (it's pretty self-explanatory).
  55  *
  56  * -------------------------------------------------------------------------- */
  57
  58 #ifndef CMM_H
  59 #define CMM_H
  60
  61 /*
  62  * In files that are included into both C and C-- (and perhaps
  63  * Haskell) sources, we sometimes need to conditionally compile bits
  64  * depending on the language.  CMINUSMINUS==1 in .cmm sources:
  65  */
  66 #define CMINUSMINUS 1
  67
  68 #include "ghcconfig.h"
  69 #include "RtsConfig.h"
  70
  71 /* -----------------------------------------------------------------------------
  72    Types
  73
  74    The following synonyms for C-- types are declared here:
  75
  76      I8, I16, I32, I64    MachRep-style names for convenience
  77
  78      W_                   is shorthand for the word type (== StgWord)
  79      F_                   shorthand for float  (F_ == StgFloat == C's float)
  80      D_                   shorthand for double (D_ == StgDouble == C's double)
  81
  82      CInt                 has the same size as an int in C on this platform
  83      CLong                has the same size as a long in C on this platform
  84
  85   --------------------------------------------------------------------------- */
  86
  87 #define I8  bits8
  88 #define I16 bits16
  89 #define I32 bits32
  90 #define I64 bits64
  91
  92 #if SIZEOF_VOID_P == 4
  93 #define W_ bits32
  94 #elif SIZEOF_VOID_P == 8
  95 #define W_ bits64
  96 #else
  97 #error Unknown word size
  98 #endif
  99
 100 #if SIZEOF_INT == 4
 101 #define CInt bits32
 102 #elif SIZEOF_INT == 8
 103 #define CInt bits64
 104 #else
 105 #error Unknown int size
 106 #endif
 107
 108 #if SIZEOF_LONG == 4
 109 #define CLong bits32
 110 #elif SIZEOF_LONG == 8
 111 #define CLong bits64
 112 #else
 113 #error Unknown long size
 114 #endif
 115
 116 #define F_ float32
 117 #define D_ float64
 118 #define L_ bits64
 119
 120 #define SIZEOF_StgDouble 8
 121 #define SIZEOF_StgWord64 8
 122
 123 /* -----------------------------------------------------------------------------
 124    Misc useful stuff
 125    -------------------------------------------------------------------------- */
 126
 127 #define NULL (0::W_)
 128
 129 #define STRING(name,str)                        \
 130   section "rodata" {                            \
 131         name : bits8[] str;                     \
 132   }                                             \
 133
 134 /* -----------------------------------------------------------------------------
 135    Byte/word macros
 136
 137    Everything in C-- is in byte offsets (well, most things).  We use
 138    some macros to allow us to express offsets in words and to try to
 139    avoid byte/word confusion.
 140    -------------------------------------------------------------------------- */
 141
 142 #define SIZEOF_W  SIZEOF_VOID_P
 143 #define W_MASK    (SIZEOF_W-1)
 144
 145 #if SIZEOF_W == 4
 146 #define W_SHIFT 2
 147 #elif SIZEOF_W == 8
 148 #define W_SHIFT 4
 149 #endif
 150
 151 /* Converting quantities of words to bytes */
 152 #define WDS(n) ((n)*SIZEOF_W)
 153
 154 /*
 155  * Converting quantities of bytes to words
 156  * NB. these work on *unsigned* values only
 157  */
 158 #define BYTES_TO_WDS(n) ((n) / SIZEOF_W)
 159 #define ROUNDUP_BYTES_TO_WDS(n) (((n) + SIZEOF_W - 1) / SIZEOF_W)
 160
 161 /* TO_W_(n) converts n to W_ type from a smaller type */
 162 #if SIZEOF_W == 4
 163 #define TO_W_(x) %sx32(x)
 164 #define HALF_W_(x) %lobits16(x)
 165 #elif SIZEOF_W == 8
 166 #define TO_W_(x) %sx64(x)
 167 #define HALF_W_(x) %lobits32(x)
 168 #endif
 169
 170 #if SIZEOF_INT == 4 && SIZEOF_W == 8
 171 #define W_TO_INT(x) %lobits32(x)
 172 #elif SIZEOF_INT == SIZEOF_W
 173 #define W_TO_INT(x) (x)
 174 #endif
 175
 176 /* -----------------------------------------------------------------------------
 177    Heap/stack access, and adjusting the heap/stack pointers.
 178    -------------------------------------------------------------------------- */
 179
 180 #define Sp(n)  W_[Sp + WDS(n)]
 181 #define Hp(n)  W_[Hp + WDS(n)]
 182
 183 #define Sp_adj(n) Sp = Sp + WDS(n)
 184 #define Hp_adj(n) Hp = Hp + WDS(n)
 185
 186 /* -----------------------------------------------------------------------------
 187    Assertions and Debuggery
 188    -------------------------------------------------------------------------- */
 189
 190 #ifdef DEBUG
 191 #define ASSERT(predicate)                       \
 192         if (predicate) {                        \
 193             /*null*/;                           \
 194         } else {                                \
 195             foreign "C" _assertFail(NULL, __LINE__); \
 196         }
 197 #else
 198 #define ASSERT(p) /* nothing */
 199 #endif
 200
 201 #ifdef DEBUG
 202 #define DEBUG_ONLY(s) s
 203 #else
 204 #define DEBUG_ONLY(s) /* nothing */
 205 #endif
 206
 207 /*
 208  * The IF_DEBUG macro is useful for debug messages that depend on one
 209  * of the RTS debug options.  For example:
 210  *
 211  *   IF_DEBUG(RtsFlags_DebugFlags_apply,
 212  *      foreign "C" fprintf(stderr, stg_ap_0_ret_str));
 213  *
 214  * Note the syntax is slightly different to the C version of this macro.
 215  */
 216 #ifdef DEBUG
 217 #define IF_DEBUG(c,s)  if (RtsFlags_DebugFlags_##c(RtsFlags)) { s; }
 218 #else
 219 #define IF_DEBUG(c,s)  /* nothing */
 220 #endif
 221
 222 /* -----------------------------------------------------------------------------
 223    Entering
 224
 225    It isn't safe to "enter" every closure.  Functions in particular
 226    have no entry code as such; their entry point contains the code to
 227    apply the function.
 228
 229    ToDo: range should end in N_CLOSURE_TYPES-1, not N_CLOSURE_TYPES,
 230    but switch doesn't allow us to use exprs there yet.
 231    -------------------------------------------------------------------------- */
 232
 233 #define ENTER()                                         \
 234  again:                                                 \
 235   switch [INVALID_OBJECT .. N_CLOSURE_TYPES]            \
 236          (TO_W_( %INFO_TYPE(%GET_STD_INFO(R1)) )) {     \
 237   case                                                  \
 238     IND,                                                \
 239     IND_OLDGEN,                                         \
 240     IND_PERM,                                           \
 241     IND_OLDGEN_PERM,                                    \
 242     IND_STATIC:                                         \
 243    {                                                    \
 244       R1 = StgInd_indirectee(R1);                       \
 245       goto again;                                       \
 246    }                                                    \
 247   case                                                  \
 248     BCO,                                                \
 249     FUN,                                                \
 250     FUN_1_0,                                            \
 251     FUN_0_1,                                            \
 252     FUN_2_0,                                            \
 253     FUN_1_1,                                            \
 254     FUN_0_2,                                            \
 255     FUN_STATIC,                                         \
 256     PAP:                                                \
 257    {                                                    \
 258       jump %ENTRY_CODE(Sp(0));                          \
 259    }                                                    \
 260   default:                                              \
 261    {                                                    \
 262       jump %GET_ENTRY(R1);                              \
 263    }                                                    \
 264   }
 265
 266 /* -----------------------------------------------------------------------------
 267    Constants.
 268    -------------------------------------------------------------------------- */
 269
 270 #include "Constants.h"
 271 #include "DerivedConstants.h"
 272 #include "ClosureTypes.h"
 273 #include "StgFun.h"
 274
 275 /*
 276  * Need MachRegs, because some of the RTS code is conditionally
 277  * compiled based on REG_R1, REG_R2, etc.
 278  */
 279 #define STOLEN_X86_REGS 4
 280 #include "MachRegs.h"
 281
 282 #include "Liveness.h"
 283 #include "StgLdvProf.h"
 284
 285 #undef BLOCK_SIZE
 286 #undef MBLOCK_SIZE
 287 #include "Block.h"  /* For Bdescr() */
 288
 289
 290 /* Can't think of a better place to put this. */
 291 #if SIZEOF_mp_limb_t != SIZEOF_VOID_P
 292 #error mp_limb_t != StgWord: assumptions in PrimOps.cmm are now false
 293 #endif
 294
 295 #define MyCapability()  (BaseReg - OFFSET_Capability_r)
 296
 297 /* -------------------------------------------------------------------------
 298    Allocation and garbage collection
 299    ------------------------------------------------------------------------- */
 300
 301 /*
 302  * ALLOC_PRIM is for allocating memory on the heap for a primitive
 303  * object.  It is used all over PrimOps.cmm.
 304  *
 305  * We make the simplifying assumption that the "admin" part of a
 306  * primitive closure is just the header when calculating sizes for
 307  * ticky-ticky.  It's not clear whether eg. the size field of an array
 308  * should be counted as "admin", or the various fields of a BCO.
 309  */
 310 #define ALLOC_PRIM(bytes,liveness,reentry)                      \
 311    HP_CHK_GEN_TICKY(bytes,liveness,reentry);                    \
 312    TICK_ALLOC_PRIM(SIZEOF_StgHeader,bytes-SIZEOF_StgHeader,0);  \
 313    CCCS_ALLOC(bytes);
 314
 315 /* CCS_ALLOC wants the size in words, because ccs->mem_alloc is in words */
 316 #define CCCS_ALLOC(__alloc) CCS_ALLOC(BYTES_TO_WDS(__alloc), W_[CCCS])
 317
 318 #define HP_CHK_GEN_TICKY(alloc,liveness,reentry)        \
 319    HP_CHK_GEN(alloc,liveness,reentry);                  \
 320    TICK_ALLOC_HEAP_NOCTR(alloc);
 321
 322 // allocateLocal() allocates from the nursery, so we check to see
 323 // whether the nursery is nearly empty in any function that uses
 324 // allocateLocal() - this includes many of the primops.
 325 #define MAYBE_GC(liveness,reentry)                      \
 326   if (bdescr_link(CurrentNursery) == NULL || CInt[alloc_blocks] >= CInt[alloc_blocks_lim]) {            \
 327         R9  = liveness;                                 \
 328         R10 = reentry;                                  \
 329         jump stg_gc_gen_hp;                             \
 330    }
 331
 332 /* -----------------------------------------------------------------------------
 333    Closure headers
 334    -------------------------------------------------------------------------- */
 335
 336 /*
 337  * This is really ugly, since we don't do the rest of StgHeader this
 338  * way.  The problem is that values from DerivedConstants.h cannot be
 339  * dependent on the way (SMP, PROF etc.).  For SIZEOF_StgHeader we get
 340  * the value from GHC, but it seems like too much trouble to do that
 341  * for StgThunkHeader.
 342  */
 343 #define SIZEOF_StgThunkHeader SIZEOF_StgHeader+SIZEOF_StgSMPThunkHeader
 344
 345 #define StgThunk_payload(__ptr__,__ix__) \
 346     W_[__ptr__+SIZEOF_StgThunkHeader+ WDS(__ix__)]
 347
 348 /* -----------------------------------------------------------------------------
 349    Closures
 350    -------------------------------------------------------------------------- */
 351
 352 /* The offset of the payload of an array */
 353 #define BYTE_ARR_CTS(arr)  ((arr) + SIZEOF_StgArrWords)
 354
 355 /* Getting/setting the info pointer of a closure */
 356 #define SET_INFO(p,info) StgHeader_info(p) = info
 357 #define GET_INFO(p) StgHeader_info(p)
 358
 359 /* Determine the size of an ordinary closure from its info table */
 360 #define sizeW_fromITBL(itbl) \
 361   SIZEOF_StgHeader + WDS(%INFO_PTRS(itbl)) + WDS(%INFO_NPTRS(itbl))
 362
 363 /* NB. duplicated from InfoTables.h! */
 364 #define BITMAP_SIZE(bitmap) ((bitmap) & BITMAP_SIZE_MASK)
 365 #define BITMAP_BITS(bitmap) ((bitmap) >> BITMAP_BITS_SHIFT)
 366
 367 /* Debugging macros */
 368 #define LOOKS_LIKE_INFO_PTR(p)                          \
 369    ((p) != NULL &&                                      \
 370      (TO_W_(%INFO_TYPE(%STD_INFO(p))) != INVALID_OBJECT) &&     \
 371      (TO_W_(%INFO_TYPE(%STD_INFO(p))) <  N_CLOSURE_TYPES))
 372
 373 #define LOOKS_LIKE_CLOSURE_PTR(p) (LOOKS_LIKE_INFO_PTR(GET_INFO(p)))
 374
 375 /*
 376  * The layout of the StgFunInfoExtra part of an info table changes
 377  * depending on TABLES_NEXT_TO_CODE.  So we define field access
 378  * macros which use the appropriate version here:
 379  */
 380 #ifdef TABLES_NEXT_TO_CODE
 381 /*
 382  * when TABLES_NEXT_TO_CODE, slow_apply is stored as an offset
 383  * instead of the normal pointer.
 384  */
 385
 386 #define StgFunInfoExtra_slow_apply(fun_info)    \
 387         (TO_W_(StgFunInfoExtraRev_slow_apply_offset(fun_info))    \
 388                + (fun_info) + SIZEOF_StgFunInfoExtraRev + SIZEOF_StgInfoTable)
 389
 390 #define StgFunInfoExtra_fun_type(i)   StgFunInfoExtraRev_fun_type(i)
 391 #define StgFunInfoExtra_arity(i)      StgFunInfoExtraRev_arity(i)
 392 #define StgFunInfoExtra_bitmap(i)     StgFunInfoExtraRev_bitmap(i)
 393 #else
 394 #define StgFunInfoExtra_slow_apply(i) StgFunInfoExtraFwd_slow_apply(i)
 395 #define StgFunInfoExtra_fun_type(i)   StgFunInfoExtraFwd_fun_type(i)
 396 #define StgFunInfoExtra_arity(i)      StgFunInfoExtraFwd_arity(i)
 397 #define StgFunInfoExtra_bitmap(i)     StgFunInfoExtraFwd_bitmap(i)
 398 #endif
 399
 400 /* -----------------------------------------------------------------------------
 401    Voluntary Yields/Blocks
 402
 403    We only have a generic version of this at the moment - if it turns
 404    out to be slowing us down we can make specialised ones.
 405    -------------------------------------------------------------------------- */
 406
 407 #define YIELD(liveness,reentry)                 \
 408    R9  = liveness;                              \
 409    R10 = reentry;                               \
 410    jump stg_gen_yield;
 411
 412 #define BLOCK(liveness,reentry)                 \
 413    R9  = liveness;                              \
 414    R10 = reentry;                               \
 415    jump stg_gen_block;
 416
 417 /* -----------------------------------------------------------------------------
 418    Ticky macros
 419    -------------------------------------------------------------------------- */
 420
 421 #ifdef TICKY_TICKY
 422 #define TICK_BUMP_BY(ctr,n) CLong[ctr] = CLong[ctr] + n
 423 #else
 424 #define TICK_BUMP_BY(ctr,n) /* nothing */
 425 #endif
 426
 427 #define TICK_BUMP(ctr)      TICK_BUMP_BY(ctr,1)
 428
 429 #define TICK_ENT_DYN_IND()              TICK_BUMP(ENT_DYN_IND_ctr)
 430 #define TICK_ENT_DYN_THK()              TICK_BUMP(ENT_DYN_THK_ctr)
 431 #define TICK_ENT_VIA_NODE()             TICK_BUMP(ENT_VIA_NODE_ctr)
 432 #define TICK_ENT_STATIC_IND()           TICK_BUMP(ENT_STATIC_IND_ctr)
 433 #define TICK_ENT_PERM_IND()             TICK_BUMP(ENT_PERM_IND_ctr)
 434 #define TICK_ENT_PAP()                  TICK_BUMP(ENT_PAP_ctr)
 435 #define TICK_ENT_AP()                   TICK_BUMP(ENT_AP_ctr)
 436 #define TICK_ENT_AP_STACK()             TICK_BUMP(ENT_AP_STACK_ctr)
 437 #define TICK_ENT_BH()                   TICK_BUMP(ENT_BH_ctr)
 438 #define TICK_UNKNOWN_CALL()             TICK_BUMP(UNKNOWN_CALL_ctr)
 439 #define TICK_UPDF_PUSHED()              TICK_BUMP(UPDF_PUSHED_ctr)
 440 #define TICK_CATCHF_PUSHED()            TICK_BUMP(CATCHF_PUSHED_ctr)
 441 #define TICK_UPDF_OMITTED()             TICK_BUMP(UPDF_OMITTED_ctr)
 442 #define TICK_UPD_NEW_IND()              TICK_BUMP(UPD_NEW_IND_ctr)
 443 #define TICK_UPD_NEW_PERM_IND()         TICK_BUMP(UPD_NEW_PERM_IND_ctr)
 444 #define TICK_UPD_OLD_IND()              TICK_BUMP(UPD_OLD_IND_ctr)
 445 #define TICK_UPD_OLD_PERM_IND()         TICK_BUMP(UPD_OLD_PERM_IND_ctr)
 446
 447 #define TICK_SLOW_CALL_FUN_TOO_FEW()    TICK_BUMP(SLOW_CALL_FUN_TOO_FEW_ctr)
 448 #define TICK_SLOW_CALL_FUN_CORRECT()    TICK_BUMP(SLOW_CALL_FUN_CORRECT_ctr)
 449 #define TICK_SLOW_CALL_FUN_TOO_MANY()   TICK_BUMP(SLOW_CALL_FUN_TOO_MANY_ctr)
 450 #define TICK_SLOW_CALL_PAP_TOO_FEW()    TICK_BUMP(SLOW_CALL_PAP_TOO_FEW_ctr)
 451 #define TICK_SLOW_CALL_PAP_CORRECT()    TICK_BUMP(SLOW_CALL_PAP_CORRECT_ctr)
 452 #define TICK_SLOW_CALL_PAP_TOO_MANY()   TICK_BUMP(SLOW_CALL_PAP_TOO_MANY_ctr)
 453
 454 #define TICK_SLOW_CALL_v()              TICK_BUMP(SLOW_CALL_v_ctr)
 455 #define TICK_SLOW_CALL_p()              TICK_BUMP(SLOW_CALL_p_ctr)
 456 #define TICK_SLOW_CALL_pv()             TICK_BUMP(SLOW_CALL_pv_ctr)
 457 #define TICK_SLOW_CALL_pp()             TICK_BUMP(SLOW_CALL_pp_ctr)
 458 #define TICK_SLOW_CALL_ppp()            TICK_BUMP(SLOW_CALL_ppp_ctr)
 459 #define TICK_SLOW_CALL_pppp()           TICK_BUMP(SLOW_CALL_pppp_ctr)
 460 #define TICK_SLOW_CALL_ppppp()          TICK_BUMP(SLOW_CALL_ppppp_ctr)
 461 #define TICK_SLOW_CALL_pppppp()         TICK_BUMP(SLOW_CALL_pppppp_ctr)
 462
 463 #ifdef TICKY_TICKY
 464 #define TICK_HISTO_BY(histo,n,i)                        \
 465          W_ __idx;                                      \
 466          __idx = (n);                                   \
 467          if (__idx > 8) {                               \
 468             __idx = 8;                                  \
 469          }                                              \
 470          CLong[histo##_hst + _idx*SIZEOF_LONG]          \
 471            = histo##_hst + __idx*SIZEOF_LONG] + i;
 472 #else
 473 #define TICK_HISTO_BY(histo,n,i) /* nothing */
 474 #endif
 475
 476 #define TICK_HISTO(histo,n) TICK_HISTO_BY(histo,n,1)
 477
 478 /* An unboxed tuple with n components. */
 479 #define TICK_RET_UNBOXED_TUP(n)                 \
 480   TICK_BUMP(RET_UNBOXED_TUP_ctr++);             \
 481   TICK_HISTO(RET_UNBOXED_TUP,n)
 482
 483 /*
 484  * A slow call with n arguments.  In the unevald case, this call has
 485  * already been counted once, so don't count it again.
 486  */
 487 #define TICK_SLOW_CALL(n)                       \
 488   TICK_BUMP(SLOW_CALL_ctr);                     \
 489   TICK_HISTO(SLOW_CALL,n)
 490
 491 /*
 492  * This slow call was found to be to an unevaluated function; undo the
 493  * ticks we did in TICK_SLOW_CALL.
 494  */
 495 #define TICK_SLOW_CALL_UNEVALD(n)               \
 496   TICK_BUMP(SLOW_CALL_UNEVALD_ctr);             \
 497   TICK_BUMP_BY(SLOW_CALL_ctr,-1);               \
 498   TICK_HISTO_BY(SLOW_CALL,n,-1);
 499
 500 /* Updating a closure with a new CON */
 501 #define TICK_UPD_CON_IN_NEW(n)                  \
 502   TICK_BUMP(UPD_CON_IN_NEW_ctr);                \
 503   TICK_HISTO(UPD_CON_IN_NEW,n)
 504
 505 #define TICK_ALLOC_HEAP_NOCTR(n)                \
 506     TICK_BUMP(ALLOC_HEAP_ctr);                  \
 507     TICK_BUMP_BY(ALLOC_HEAP_tot,n)
 508
 509 /* -----------------------------------------------------------------------------
 510    Misc junk
 511    -------------------------------------------------------------------------- */
 512
 513 #define TICK_MILLISECS   (1000/TICK_FREQUENCY)   /* ms per tick */
 514
 515 #endif /* CMM_H */