InfoTables.h 12.7 KB
Newer Older
1
/* ----------------------------------------------------------------------------
2
 *
3
 * (c) The GHC Team, 1998-2002
4
 *
5 6 7 8
 * Info Tables
 *
 * -------------------------------------------------------------------------- */

Simon Marlow's avatar
Simon Marlow committed
9 10
#ifndef RTS_STORAGE_INFOTABLES_H
#define RTS_STORAGE_INFOTABLES_H
11

Simon Marlow's avatar
Simon Marlow committed
12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
/* ----------------------------------------------------------------------------
   Relative pointers

   Several pointer fields in info tables are expressed as offsets
   relative to the info pointer, so that we can generate
   position-independent code.

   Note [x86-64-relative]
   There is a complication on the x86_64 platform, where pointeres are
   64 bits, but the tools don't support 64-bit relative relocations.
   However, the default memory model (small) ensures that all symbols
   have values in the lower 2Gb of the address space, so offsets all
   fit in 32 bits.  Hence we can use 32-bit offset fields.

   Somewhere between binutils-2.16.1 and binutils-2.16.91.0.6,
   support for 64-bit PC-relative relocations was added, so maybe this
   hackery can go away sometime.
   ------------------------------------------------------------------------- */

#if x86_64_TARGET_ARCH
32
#define OFFSET_FIELD(n) StgHalfInt n; StgHalfWord __pad_##n
33
#else
34
#define OFFSET_FIELD(n) StgInt n
Simon Marlow's avatar
Simon Marlow committed
35 36
#endif

37 38 39 40 41
/* -----------------------------------------------------------------------------
   Profiling info
   -------------------------------------------------------------------------- */

typedef struct {
Simon Marlow's avatar
Simon Marlow committed
42
#ifndef TABLES_NEXT_TO_CODE
43 44
    char *closure_type;
    char *closure_desc;
Simon Marlow's avatar
Simon Marlow committed
45 46 47 48
#else
    OFFSET_FIELD(closure_type_off);
    OFFSET_FIELD(closure_desc_off);
#endif
49 50
} StgProfInfo;

51 52 53 54
/* -----------------------------------------------------------------------------
   Closure flags
   -------------------------------------------------------------------------- */

55 56
/* The type flags provide quick access to certain properties of a closure. */

57
#define _HNF (1<<0)  /* head normal form?    */
58
#define _BTM (1<<1)  /* uses info->layout.bitmap */
59 60 61 62 63 64 65
#define _NS  (1<<2)  /* non-sparkable        */
#define _STA (1<<3)  /* static?              */
#define _THU (1<<4)  /* thunk?               */
#define _MUT (1<<5)  /* mutable?             */
#define _UPT (1<<6)  /* unpointed?           */
#define _SRT (1<<7)  /* has an SRT?          */
#define _IND (1<<8)  /* is an indirection?   */
66

67 68 69 70 71 72
#define isSTATIC(flags)    ((flags) &_STA)
#define isMUTABLE(flags)   ((flags) &_MUT)
#define isBITMAP(flags)    ((flags) &_BTM)
#define isTHUNK(flags)     ((flags) &_THU)
#define isUNPOINTED(flags) ((flags) &_UPT)
#define hasSRT(flags)      ((flags) &_SRT)
73

74 75
extern StgWord16 closure_flags[];

Simon Marlow's avatar
Simon Marlow committed
76
#define closureFlags(c)         (closure_flags[get_itbl(UNTAG_CLOSURE(c))->type])
77

78 79
#define closure_HNF(c)          (  closureFlags(c) & _HNF)
#define closure_BITMAP(c)       (  closureFlags(c) & _BTM)
80
#define closure_NON_SPARK(c)    ( (closureFlags(c) & _NS))
81
#define closure_SHOULD_SPARK(c) (!(closureFlags(c) & _NS))
82 83
#define closure_STATIC(c)       (  closureFlags(c) & _STA)
#define closure_THUNK(c)        (  closureFlags(c) & _THU)
84 85
#define closure_MUTABLE(c)      (  closureFlags(c) & _MUT)
#define closure_UNPOINTED(c)    (  closureFlags(c) & _UPT)
86
#define closure_SRT(c)          (  closureFlags(c) & _SRT)
87
#define closure_IND(c)          (  closureFlags(c) & _IND)
88 89 90

/* same as above but for info-ptr rather than closure */
#define ipFlags(ip)             (closure_flags[ip->type])
91

92
#define ip_HNF(ip)               (  ipFlags(ip) & _HNF)
93 94 95 96 97 98 99 100
#define ip_BITMAP(ip)            (  ipFlags(ip) & _BTM)
#define ip_SHOULD_SPARK(ip)      (!(ipFlags(ip) & _NS))
#define ip_STATIC(ip)            (  ipFlags(ip) & _STA)
#define ip_THUNK(ip)             (  ipFlags(ip) & _THU)
#define ip_MUTABLE(ip)           (  ipFlags(ip) & _MUT)
#define ip_UNPOINTED(ip)         (  ipFlags(ip) & _UPT)
#define ip_SRT(ip)               (  ipFlags(ip) & _SRT)
#define ip_IND(ip)               (  ipFlags(ip) & _IND)
101 102

/* -----------------------------------------------------------------------------
103 104 105 106 107 108
   Bitmaps

   These are used to describe the pointerhood of a sequence of words
   (usually on the stack) to the garbage collector.  The two primary
   uses are for stack frames, and functions (where we need to describe
   the layout of a PAP to the GC).
109 110

   In these bitmaps: 0 == ptr, 1 == non-ptr.
111 112
   -------------------------------------------------------------------------- */

113
/*
114
 * Small bitmaps:  for a small bitmap, we store the size and bitmap in
115 116 117
 * the same word, using the following macros.  If the bitmap doesn't
 * fit in a single word, we use a pointer to an StgLargeBitmap below.
 */
118 119 120 121
#define MK_SMALL_BITMAP(size,bits) (((bits)<<BITMAP_BITS_SHIFT) | (size))

#define BITMAP_SIZE(bitmap) ((bitmap) & BITMAP_SIZE_MASK)
#define BITMAP_BITS(bitmap) ((bitmap) >> BITMAP_BITS_SHIFT)
122

123 124 125
/*
 * A large bitmap.
 */
126
typedef struct {
127
  StgWord size;
128
  StgWord bitmap[FLEXIBLE_ARRAY];
129 130
} StgLargeBitmap;

131 132 133 134 135 136 137 138 139
/* -----------------------------------------------------------------------------
   SRTs  (Static Reference Tables)

   These tables are used to keep track of the static objects referred
   to by the code for a closure or stack frame, so that we can follow
   static data references from code and thus accurately
   garbage-collect CAFs.
   -------------------------------------------------------------------------- */

140
/* An SRT is just an array of closure pointers: */
141 142
typedef StgClosure* StgSRT[];

143 144 145 146 147 148 149 150
/*
 * Each info table refers to some subset of the closure pointers in an
 * SRT.  It does this using a pair of an StgSRT pointer and a
 * half-word bitmap.  If the half-word bitmap isn't large enough, then
 * we fall back to a large SRT, including an unbounded bitmap.  If the
 * half-word bitmap is set to all ones (0xffff), then the StgSRT
 * pointer instead points to an StgLargeSRT:
 */
151 152 153 154 155
typedef struct StgLargeSRT_ {
    StgSRT *srt;
    StgLargeBitmap l;
} StgLargeSRT;

156 157 158
/* ----------------------------------------------------------------------------
   Info Tables
   ------------------------------------------------------------------------- */
159

160 161 162 163 164
/*
 * Stuff describing the closure layout.  Well, actually, it might
 * contain the selector index for a THUNK_SELECTOR.  This union is one
 * word long.
 */
165
typedef union {
166 167 168
    struct {                    /* Heap closure payload layout: */
        StgHalfWord ptrs;       /* number of pointers */
        StgHalfWord nptrs;      /* number of non-pointers */
169
    } payload;
170 171 172

    StgWord bitmap;               /* word-sized bit pattern describing */
                                  /*  a stack frame: see below */
173

174
#ifndef TABLES_NEXT_TO_CODE
175
    StgLargeBitmap* large_bitmap; /* pointer to large bitmap structure */
176
#else
177
    OFFSET_FIELD(large_bitmap_offset);  /* offset from info table to large bitmap structure */
178
#endif
179 180

    StgWord selector_offset;      /* used in THUNK_SELECTORs */
sof's avatar
sof committed
181

182 183 184
} StgClosureInfo;


185 186 187
/*
 * The "standard" part of an info table.  Every info table has this bit.
 */
Simon Marlow's avatar
Simon Marlow committed
188
typedef struct StgInfoTable_ {
189

190
#if !defined(TABLES_NEXT_TO_CODE)
191
    StgFunPtr       entry;      /* pointer to the entry code */
192 193
#endif

sof's avatar
sof committed
194
#ifdef PROFILING
195
    StgProfInfo     prof;
sof's avatar
sof committed
196
#endif
197

198
    StgClosureInfo  layout;     /* closure layout info (one word) */
199

200
    StgHalfWord     type;       /* closure type */
201 202 203 204 205 206
    StgHalfWord     srt_bitmap;
       /* In a CONSTR:
            - the constructor tag
          In a FUN/THUNK
            - a bitmap of SRT entries
       */
207

208
#ifdef TABLES_NEXT_TO_CODE
209
    StgCode         code[FLEXIBLE_ARRAY];
210
#endif
Simon Marlow's avatar
Simon Marlow committed
211
} *StgInfoTablePtr;
212

213 214 215 216 217 218 219 220 221 222

/* -----------------------------------------------------------------------------
   Function info tables

   This is the general form of function info tables.  The compiler
   will omit some of the fields in common cases:

   -  If fun_type is not ARG_GEN or ARG_GEN_BIG, then the slow_apply
      and bitmap fields may be left out (they are at the end, so omitting
      them doesn't affect the layout).
223

224
   -  If srt_bitmap (in the std info table part) is zero, then the srt
225 226 227 228
      field may be omitted.  This only applies if the slow_apply and
      bitmap fields have also been omitted.
   -------------------------------------------------------------------------- */

Simon Marlow's avatar
Simon Marlow committed
229
typedef struct StgFunInfoExtraRev_ {
230
    OFFSET_FIELD(slow_apply_offset); /* apply to args on the stack */
231 232 233
    union {
        StgWord bitmap;
        OFFSET_FIELD(bitmap_offset);    /* arg ptr/nonptr bitmap */
234
    } b;
235
    OFFSET_FIELD(srt_offset);   /* pointer to the SRT table */
236 237
    StgHalfWord    fun_type;    /* function type */
    StgHalfWord    arity;       /* function arity */
238 239
} StgFunInfoExtraRev;

Simon Marlow's avatar
Simon Marlow committed
240
typedef struct StgFunInfoExtraFwd_ {
241 242
    StgHalfWord    fun_type;    /* function type */
    StgHalfWord    arity;       /* function arity */
243
    StgSRT         *srt;        /* pointer to the SRT table */
244
    union { /* union for compat. with TABLES_NEXT_TO_CODE version */
245
        StgWord        bitmap;  /* arg ptr/nonptr bitmap */
246
    } b;
247
    StgFun         *slow_apply; /* apply to args on the stack */
248 249 250 251 252 253 254 255 256
} StgFunInfoExtraFwd;

typedef struct {
#if defined(TABLES_NEXT_TO_CODE)
    StgFunInfoExtraRev f;
    StgInfoTable i;
#else
    StgInfoTable i;
    StgFunInfoExtraFwd f;
257 258 259
#endif
} StgFunInfoTable;

260 261 262
// canned bitmap for each arg type, indexed by constants in FunTypes.h
extern StgWord stg_arg_bitmaps[];

263 264 265 266
/* -----------------------------------------------------------------------------
   Return info tables
   -------------------------------------------------------------------------- */

267 268 269 270
/*
 * When info tables are laid out backwards, we can omit the SRT
 * pointer iff srt_bitmap is zero.
 */
271

272
typedef struct {
273
#if defined(TABLES_NEXT_TO_CODE)
274
    OFFSET_FIELD(srt_offset);   /* offset to the SRT table */
275
    StgInfoTable i;
276 277
#else
    StgInfoTable i;
278
    StgSRT      *srt;   /* pointer to the SRT table */
279 280 281 282 283 284 285
#endif
} StgRetInfoTable;

/* -----------------------------------------------------------------------------
   Thunk info tables
   -------------------------------------------------------------------------- */

286 287 288 289
/*
 * When info tables are laid out backwards, we can omit the SRT
 * pointer iff srt_bitmap is zero.
 */
290

Simon Marlow's avatar
Simon Marlow committed
291
typedef struct StgThunkInfoTable_ {
292 293 294
#if !defined(TABLES_NEXT_TO_CODE)
    StgInfoTable i;
#endif
295
#if defined(TABLES_NEXT_TO_CODE)
296
    OFFSET_FIELD(srt_offset);   /* offset to the SRT table */
297
#else
298
    StgSRT         *srt;        /* pointer to the SRT table */
299
#endif
300 301
#if defined(TABLES_NEXT_TO_CODE)
    StgInfoTable i;
302
#endif
303
} StgThunkInfoTable;
304

305 306 307 308
/* -----------------------------------------------------------------------------
   Constructor info tables
   -------------------------------------------------------------------------- */

Simon Marlow's avatar
Simon Marlow committed
309
typedef struct StgConInfoTable_ {
310 311 312 313
#if !defined(TABLES_NEXT_TO_CODE)
    StgInfoTable i;
#endif

314
#if defined(TABLES_NEXT_TO_CODE)
315
    OFFSET_FIELD(con_desc); // the name of the data constructor
316
                            // as: Package:Module.Name
317 318
#else
    char *con_desc;
Simon Marlow's avatar
Simon Marlow committed
319
#endif
320 321 322 323 324 325

#if defined(TABLES_NEXT_TO_CODE)
    StgInfoTable i;
#endif
} StgConInfoTable;

326 327 328 329 330

/* -----------------------------------------------------------------------------
   Accessor macros for fields that might be offsets (C version)
   -------------------------------------------------------------------------- */

331 332 333 334
/*
 * GET_SRT(info)
 * info must be a Stg[Ret|Thunk]InfoTable* (an info table that has a SRT)
 */
335 336 337 338 339 340
#ifdef TABLES_NEXT_TO_CODE
#define GET_SRT(info) ((StgSRT*) (((StgWord) ((info)+1)) + (info)->srt_offset))
#else
#define GET_SRT(info) ((info)->srt)
#endif

341 342 343 344 345 346 347 348 349 350
/*
 * GET_CON_DESC(info)
 * info must be a StgConInfoTable*.
 */
#ifdef TABLES_NEXT_TO_CODE
#define GET_CON_DESC(info) ((char *)((StgWord)((info)+1) + (info->con_desc)))
#else
#define GET_CON_DESC(info) ((info)->con_desc)
#endif

351 352 353 354
/*
 * GET_FUN_SRT(info)
 * info must be a StgFunInfoTable*
 */
355 356 357 358 359 360 361 362 363 364 365 366 367 368 369
#ifdef TABLES_NEXT_TO_CODE
#define GET_FUN_SRT(info) ((StgSRT*) (((StgWord) ((info)+1)) + (info)->f.srt_offset))
#else
#define GET_FUN_SRT(info) ((info)->f.srt)
#endif

#ifdef TABLES_NEXT_TO_CODE
#define GET_LARGE_BITMAP(info) ((StgLargeBitmap*) (((StgWord) ((info)+1)) \
                                        + (info)->layout.large_bitmap_offset))
#else
#define GET_LARGE_BITMAP(info) ((info)->layout.large_bitmap)
#endif

#ifdef TABLES_NEXT_TO_CODE
#define GET_FUN_LARGE_BITMAP(info) ((StgLargeBitmap*) (((StgWord) ((info)+1)) \
370
                                        + (info)->f.b.bitmap_offset))
371
#else
372
#define GET_FUN_LARGE_BITMAP(info) ((StgLargeBitmap*) ((info)->f.b.bitmap))
373 374
#endif

Simon Marlow's avatar
Simon Marlow committed
375 376 377 378 379 380 381 382 383 384 385 386 387
/*
 * GET_PROF_TYPE, GET_PROF_DESC
 */
#ifdef TABLES_NEXT_TO_CODE
#define GET_PROF_TYPE(info) ((char *)((StgWord)((info)+1) + (info->prof.closure_type_off)))
#else
#define GET_PROF_TYPE(info) ((info)->prof.closure_type)
#endif
#ifdef TABLES_NEXT_TO_CODE
#define GET_PROF_DESC(info) ((char *)((StgWord)((info)+1) + (info->prof.closure_desc_off)))
#else
#define GET_PROF_DESC(info) ((info)->prof.closure_desc)
#endif
Simon Marlow's avatar
Simon Marlow committed
388 389

#endif /* RTS_STORAGE_INFOTABLES_H */