gcc/hard-reg-set.h

   1 /* Sets (bit vectors) of hard registers, and operations on them.
   2    Copyright (C) 1987, 1992, 1994, 2000 Free Software Foundation, Inc.
   3
   4 This file is part of GCC
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 2, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING.  If not, write to the Free
  18 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  19 02111-1307, USA.  */
  20
  21 #ifndef GCC_HARD_REG_SET_H
  22 #define GCC_HARD_REG_SET_H
  23
  24 /* Define the type of a set of hard registers.  */
  25
  26 /* HARD_REG_ELT_TYPE is a typedef of the unsigned integral type which
  27    will be used for hard reg sets, either alone or in an array.
  28
  29    If HARD_REG_SET is a macro, its definition is HARD_REG_ELT_TYPE,
  30    and it has enough bits to represent all the target machine's hard
  31    registers.  Otherwise, it is a typedef for a suitably sized array
  32    of HARD_REG_ELT_TYPEs.  HARD_REG_SET_LONGS is defined as how many.
  33
  34    Note that lots of code assumes that the first part of a regset is
  35    the same format as a HARD_REG_SET.  To help make sure this is true,
  36    we only try the widest integer mode (HOST_WIDE_INT) instead of all the
  37    smaller types.  This approach loses only if there are a very few
  38    registers and then only in the few cases where we have an array of
  39    HARD_REG_SETs, so it needn't be as complex as it used to be.  */
  40
  41 typedef unsigned HOST_WIDE_INT HARD_REG_ELT_TYPE;
  42
  43 #if FIRST_PSEUDO_REGISTER <= HOST_BITS_PER_WIDE_INT
  44
  45 #define HARD_REG_SET HARD_REG_ELT_TYPE
  46
  47 #else
  48
  49 #define HARD_REG_SET_LONGS \
  50  ((FIRST_PSEUDO_REGISTER + HOST_BITS_PER_WIDE_INT - 1)  \
  51   / HOST_BITS_PER_WIDE_INT)
  52 typedef HARD_REG_ELT_TYPE HARD_REG_SET[HARD_REG_SET_LONGS];
  53
  54 #endif
  55
  56 /* HARD_CONST is used to cast a constant to the appropriate type
  57    for use with a HARD_REG_SET.  */
  58
  59 #define HARD_CONST(X) ((HARD_REG_ELT_TYPE) (X))
  60
  61 /* Define macros SET_HARD_REG_BIT, CLEAR_HARD_REG_BIT and TEST_HARD_REG_BIT
  62    to set, clear or test one bit in a hard reg set of type HARD_REG_SET.
  63    All three take two arguments: the set and the register number.
  64
  65    In the case where sets are arrays of longs, the first argument
  66    is actually a pointer to a long.
  67
  68    Define two macros for initializing a set:
  69    CLEAR_HARD_REG_SET and SET_HARD_REG_SET.
  70    These take just one argument.
  71
  72    Also define macros for copying hard reg sets:
  73    COPY_HARD_REG_SET and COMPL_HARD_REG_SET.
  74    These take two arguments TO and FROM; they read from FROM
  75    and store into TO.  COMPL_HARD_REG_SET complements each bit.
  76
  77    Also define macros for combining hard reg sets:
  78    IOR_HARD_REG_SET and AND_HARD_REG_SET.
  79    These take two arguments TO and FROM; they read from FROM
  80    and combine bitwise into TO.  Define also two variants
  81    IOR_COMPL_HARD_REG_SET and AND_COMPL_HARD_REG_SET
  82    which use the complement of the set FROM.
  83
  84    Also define GO_IF_HARD_REG_SUBSET (X, Y, TO):
  85    if X is a subset of Y, go to TO.
  86 */
  87
  88 #ifdef HARD_REG_SET
  89
  90 #define SET_HARD_REG_BIT(SET, BIT)  \
  91  ((SET) |= HARD_CONST (1) << (BIT))
  92 #define CLEAR_HARD_REG_BIT(SET, BIT)  \
  93  ((SET) &= ~(HARD_CONST (1) << (BIT)))
  94 #define TEST_HARD_REG_BIT(SET, BIT)  \
  95  (!!((SET) & (HARD_CONST (1) << (BIT))))
  96
  97 #define CLEAR_HARD_REG_SET(TO) ((TO) = HARD_CONST (0))
  98 #define SET_HARD_REG_SET(TO) ((TO) = ~ HARD_CONST (0))
  99
 100 #define COPY_HARD_REG_SET(TO, FROM) ((TO) = (FROM))
 101 #define COMPL_HARD_REG_SET(TO, FROM) ((TO) = ~(FROM))
 102
 103 #define IOR_HARD_REG_SET(TO, FROM) ((TO) |= (FROM))
 104 #define IOR_COMPL_HARD_REG_SET(TO, FROM) ((TO) |= ~ (FROM))
 105 #define AND_HARD_REG_SET(TO, FROM) ((TO) &= (FROM))
 106 #define AND_COMPL_HARD_REG_SET(TO, FROM) ((TO) &= ~ (FROM))
 107
 108 #define GO_IF_HARD_REG_SUBSET(X,Y,TO) if (HARD_CONST (0) == ((X) & ~(Y))) goto TO
 109
 110 #define GO_IF_HARD_REG_EQUAL(X,Y,TO) if ((X) == (Y)) goto TO
 111
 112 #else
 113
 114 #define UHOST_BITS_PER_WIDE_INT ((unsigned) HOST_BITS_PER_WIDE_INT)
 115
 116 #define SET_HARD_REG_BIT(SET, BIT)              \
 117   ((SET)[(BIT) / UHOST_BITS_PER_WIDE_INT]       \
 118    |= HARD_CONST (1) << ((BIT) % UHOST_BITS_PER_WIDE_INT))
 119
 120 #define CLEAR_HARD_REG_BIT(SET, BIT)            \
 121   ((SET)[(BIT) / UHOST_BITS_PER_WIDE_INT]       \
 122    &= ~(HARD_CONST (1) << ((BIT) % UHOST_BITS_PER_WIDE_INT)))
 123
 124 #define TEST_HARD_REG_BIT(SET, BIT)             \
 125   (!!((SET)[(BIT) / UHOST_BITS_PER_WIDE_INT]    \
 126       & (HARD_CONST (1) << ((BIT) % UHOST_BITS_PER_WIDE_INT))))
 127
 128 #if FIRST_PSEUDO_REGISTER <= 2*HOST_BITS_PER_WIDE_INT
 129 #define CLEAR_HARD_REG_SET(TO)  \
 130 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO);                        \
 131      scan_tp_[0] = 0;                                           \
 132      scan_tp_[1] = 0; } while (0)
 133
 134 #define SET_HARD_REG_SET(TO)  \
 135 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO);                        \
 136      scan_tp_[0] = -1;                                          \
 137      scan_tp_[1] = -1; } while (0)
 138
 139 #define COPY_HARD_REG_SET(TO, FROM)  \
 140 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 141      scan_tp_[0] = scan_fp_[0];                                 \
 142      scan_tp_[1] = scan_fp_[1]; } while (0)
 143
 144 #define COMPL_HARD_REG_SET(TO, FROM)  \
 145 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 146      scan_tp_[0] = ~ scan_fp_[0];                               \
 147      scan_tp_[1] = ~ scan_fp_[1]; } while (0)
 148
 149 #define AND_HARD_REG_SET(TO, FROM)  \
 150 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 151      scan_tp_[0] &= scan_fp_[0];                                \
 152      scan_tp_[1] &= scan_fp_[1]; } while (0)
 153
 154 #define AND_COMPL_HARD_REG_SET(TO, FROM)  \
 155 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 156      scan_tp_[0] &= ~ scan_fp_[0];                              \
 157      scan_tp_[1] &= ~ scan_fp_[1]; } while (0)
 158
 159 #define IOR_HARD_REG_SET(TO, FROM)  \
 160 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 161      scan_tp_[0] |= scan_fp_[0];                                \
 162      scan_tp_[1] |= scan_fp_[1]; } while (0)
 163
 164 #define IOR_COMPL_HARD_REG_SET(TO, FROM)  \
 165 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 166      scan_tp_[0] |= ~ scan_fp_[0];                              \
 167      scan_tp_[1] |= ~ scan_fp_[1]; } while (0)
 168
 169 #define GO_IF_HARD_REG_SUBSET(X,Y,TO)  \
 170 do { HARD_REG_ELT_TYPE *scan_xp_ = (X), *scan_yp_ = (Y);        \
 171      if ((0 == (scan_xp_[0] & ~ scan_yp_[0]))                   \
 172          && (0 == (scan_xp_[1] & ~ scan_yp_[1])))               \
 173         goto TO; } while (0)
 174
 175 #define GO_IF_HARD_REG_EQUAL(X,Y,TO)  \
 176 do { HARD_REG_ELT_TYPE *scan_xp_ = (X), *scan_yp_ = (Y);        \
 177      if ((scan_xp_[0] == scan_yp_[0])                           \
 178          && (scan_xp_[1] == scan_yp_[1]))                       \
 179         goto TO; } while (0)
 180
 181 #else
 182 #if FIRST_PSEUDO_REGISTER <= 3*HOST_BITS_PER_WIDE_INT
 183 #define CLEAR_HARD_REG_SET(TO)  \
 184 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO);                        \
 185      scan_tp_[0] = 0;                                           \
 186      scan_tp_[1] = 0;                                           \
 187      scan_tp_[2] = 0; } while (0)
 188
 189 #define SET_HARD_REG_SET(TO)  \
 190 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO);                        \
 191      scan_tp_[0] = -1;                                          \
 192      scan_tp_[1] = -1;                                          \
 193      scan_tp_[2] = -1; } while (0)
 194
 195 #define COPY_HARD_REG_SET(TO, FROM)  \
 196 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 197      scan_tp_[0] = scan_fp_[0];                                 \
 198      scan_tp_[1] = scan_fp_[1];                                 \
 199      scan_tp_[2] = scan_fp_[2]; } while (0)
 200
 201 #define COMPL_HARD_REG_SET(TO, FROM)  \
 202 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 203      scan_tp_[0] = ~ scan_fp_[0];                               \
 204      scan_tp_[1] = ~ scan_fp_[1];                               \
 205      scan_tp_[2] = ~ scan_fp_[2]; } while (0)
 206
 207 #define AND_HARD_REG_SET(TO, FROM)  \
 208 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 209      scan_tp_[0] &= scan_fp_[0];                                \
 210      scan_tp_[1] &= scan_fp_[1];                                \
 211      scan_tp_[2] &= scan_fp_[2]; } while (0)
 212
 213 #define AND_COMPL_HARD_REG_SET(TO, FROM)  \
 214 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 215      scan_tp_[0] &= ~ scan_fp_[0];                              \
 216      scan_tp_[1] &= ~ scan_fp_[1];                              \
 217      scan_tp_[2] &= ~ scan_fp_[2]; } while (0)
 218
 219 #define IOR_HARD_REG_SET(TO, FROM)  \
 220 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 221      scan_tp_[0] |= scan_fp_[0];                                \
 222      scan_tp_[1] |= scan_fp_[1];                                \
 223      scan_tp_[2] |= scan_fp_[2]; } while (0)
 224
 225 #define IOR_COMPL_HARD_REG_SET(TO, FROM)  \
 226 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 227      scan_tp_[0] |= ~ scan_fp_[0];                              \
 228      scan_tp_[1] |= ~ scan_fp_[1];                              \
 229      scan_tp_[2] |= ~ scan_fp_[2]; } while (0)
 230
 231 #define GO_IF_HARD_REG_SUBSET(X,Y,TO)  \
 232 do { HARD_REG_ELT_TYPE *scan_xp_ = (X), *scan_yp_ = (Y);        \
 233      if ((0 == (scan_xp_[0] & ~ scan_yp_[0]))                   \
 234          && (0 == (scan_xp_[1] & ~ scan_yp_[1]))                \
 235          && (0 == (scan_xp_[2] & ~ scan_yp_[2])))               \
 236         goto TO; } while (0)
 237
 238 #define GO_IF_HARD_REG_EQUAL(X,Y,TO)  \
 239 do { HARD_REG_ELT_TYPE *scan_xp_ = (X), *scan_yp_ = (Y);        \
 240      if ((scan_xp_[0] == scan_yp_[0])                           \
 241          && (scan_xp_[1] == scan_yp_[1])                        \
 242          && (scan_xp_[2] == scan_yp_[2]))                       \
 243         goto TO; } while (0)
 244
 245 #else
 246 #if FIRST_PSEUDO_REGISTER <= 4*HOST_BITS_PER_WIDE_INT
 247 #define CLEAR_HARD_REG_SET(TO)  \
 248 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO);                        \
 249      scan_tp_[0] = 0;                                           \
 250      scan_tp_[1] = 0;                                           \
 251      scan_tp_[2] = 0;                                           \
 252      scan_tp_[3] = 0; } while (0)
 253
 254 #define SET_HARD_REG_SET(TO)  \
 255 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO);                        \
 256      scan_tp_[0] = -1;                                          \
 257      scan_tp_[1] = -1;                                          \
 258      scan_tp_[2] = -1;                                          \
 259      scan_tp_[3] = -1; } while (0)
 260
 261 #define COPY_HARD_REG_SET(TO, FROM)  \
 262 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 263      scan_tp_[0] = scan_fp_[0];                                 \
 264      scan_tp_[1] = scan_fp_[1];                                 \
 265      scan_tp_[2] = scan_fp_[2];                                 \
 266      scan_tp_[3] = scan_fp_[3]; } while (0)
 267
 268 #define COMPL_HARD_REG_SET(TO, FROM)  \
 269 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 270      scan_tp_[0] = ~ scan_fp_[0];                               \
 271      scan_tp_[1] = ~ scan_fp_[1];                               \
 272      scan_tp_[2] = ~ scan_fp_[2];                               \
 273      scan_tp_[3] = ~ scan_fp_[3]; } while (0)
 274
 275 #define AND_HARD_REG_SET(TO, FROM)  \
 276 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 277      scan_tp_[0] &= scan_fp_[0];                                \
 278      scan_tp_[1] &= scan_fp_[1];                                \
 279      scan_tp_[2] &= scan_fp_[2];                                \
 280      scan_tp_[3] &= scan_fp_[3]; } while (0)
 281
 282 #define AND_COMPL_HARD_REG_SET(TO, FROM)  \
 283 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 284      scan_tp_[0] &= ~ scan_fp_[0];                              \
 285      scan_tp_[1] &= ~ scan_fp_[1];                              \
 286      scan_tp_[2] &= ~ scan_fp_[2];                              \
 287      scan_tp_[3] &= ~ scan_fp_[3]; } while (0)
 288
 289 #define IOR_HARD_REG_SET(TO, FROM)  \
 290 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 291      scan_tp_[0] |= scan_fp_[0];                                \
 292      scan_tp_[1] |= scan_fp_[1];                                \
 293      scan_tp_[2] |= scan_fp_[2];                                \
 294      scan_tp_[3] |= scan_fp_[3]; } while (0)
 295
 296 #define IOR_COMPL_HARD_REG_SET(TO, FROM)  \
 297 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 298      scan_tp_[0] |= ~ scan_fp_[0];                              \
 299      scan_tp_[1] |= ~ scan_fp_[1];                              \
 300      scan_tp_[2] |= ~ scan_fp_[2];                              \
 301      scan_tp_[3] |= ~ scan_fp_[3]; } while (0)
 302
 303 #define GO_IF_HARD_REG_SUBSET(X,Y,TO)  \
 304 do { HARD_REG_ELT_TYPE *scan_xp_ = (X), *scan_yp_ = (Y);        \
 305      if ((0 == (scan_xp_[0] & ~ scan_yp_[0]))                   \
 306          && (0 == (scan_xp_[1] & ~ scan_yp_[1]))                \
 307          && (0 == (scan_xp_[2] & ~ scan_yp_[2]))                \
 308          && (0 == (scan_xp_[3] & ~ scan_yp_[3])))               \
 309         goto TO; } while (0)
 310
 311 #define GO_IF_HARD_REG_EQUAL(X,Y,TO)  \
 312 do { HARD_REG_ELT_TYPE *scan_xp_ = (X), *scan_yp_ = (Y);        \
 313      if ((scan_xp_[0] == scan_yp_[0])                           \
 314          && (scan_xp_[1] == scan_yp_[1])                        \
 315          && (scan_xp_[2] == scan_yp_[2])                        \
 316          && (scan_xp_[3] == scan_yp_[3]))                       \
 317         goto TO; } while (0)
 318
 319 #else /* FIRST_PSEUDO_REGISTER > 3*HOST_BITS_PER_WIDE_INT */
 320
 321 #define CLEAR_HARD_REG_SET(TO)  \
 322 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO);                        \
 323      int i;                                                     \
 324      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 325        *scan_tp_++ = 0; } while (0)
 326
 327 #define SET_HARD_REG_SET(TO)  \
 328 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO);                        \
 329      int i;                                                     \
 330      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 331        *scan_tp_++ = -1; } while (0)
 332
 333 #define COPY_HARD_REG_SET(TO, FROM)  \
 334 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 335      int i;                                                     \
 336      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 337        *scan_tp_++ = *scan_fp_++; } while (0)
 338
 339 #define COMPL_HARD_REG_SET(TO, FROM)  \
 340 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 341      int i;                                                     \
 342      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 343        *scan_tp_++ = ~ *scan_fp_++; } while (0)
 344
 345 #define AND_HARD_REG_SET(TO, FROM)  \
 346 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 347      int i;                                                     \
 348      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 349        *scan_tp_++ &= *scan_fp_++; } while (0)
 350
 351 #define AND_COMPL_HARD_REG_SET(TO, FROM)  \
 352 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 353      int i;                                                     \
 354      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 355        *scan_tp_++ &= ~ *scan_fp_++; } while (0)
 356
 357 #define IOR_HARD_REG_SET(TO, FROM)  \
 358 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 359      int i;                                                     \
 360      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 361        *scan_tp_++ |= *scan_fp_++; } while (0)
 362
 363 #define IOR_COMPL_HARD_REG_SET(TO, FROM)  \
 364 do { HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM);    \
 365      int i;                                                     \
 366      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 367        *scan_tp_++ |= ~ *scan_fp_++; } while (0)
 368
 369 #define GO_IF_HARD_REG_SUBSET(X,Y,TO)  \
 370 do { HARD_REG_ELT_TYPE *scan_xp_ = (X), *scan_yp_ = (Y);        \
 371      int i;                                                     \
 372      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 373        if (0 != (*scan_xp_++ & ~ *scan_yp_++)) break;           \
 374      if (i == HARD_REG_SET_LONGS) goto TO; } while (0)
 375
 376 #define GO_IF_HARD_REG_EQUAL(X,Y,TO)  \
 377 do { HARD_REG_ELT_TYPE *scan_xp_ = (X), *scan_yp_ = (Y);        \
 378      int i;                                                     \
 379      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 380        if (*scan_xp_++ != *scan_yp_++) break;                   \
 381      if (i == HARD_REG_SET_LONGS) goto TO; } while (0)
 382
 383 #endif
 384 #endif
 385 #endif
 386 #endif
 387
 388 /* Define some standard sets of registers.  */
 389
 390 /* Indexed by hard register number, contains 1 for registers
 391    that are fixed use (stack pointer, pc, frame pointer, etc.).
 392    These are the registers that cannot be used to allocate
 393    a pseudo reg whose life does not cross calls.  */
 394
 395 extern char fixed_regs[FIRST_PSEUDO_REGISTER];
 396
 397 /* The same info as a HARD_REG_SET.  */
 398
 399 extern HARD_REG_SET fixed_reg_set;
 400
 401 /* Indexed by hard register number, contains 1 for registers
 402    that are fixed use or are clobbered by function calls.
 403    These are the registers that cannot be used to allocate
 404    a pseudo reg whose life crosses calls.  */
 405
 406 extern char call_used_regs[FIRST_PSEUDO_REGISTER];
 407
 408 #ifdef CALL_REALLY_USED_REGISTERS
 409 extern char call_really_used_regs[];
 410 #endif
 411
 412 /* The same info as a HARD_REG_SET.  */
 413
 414 extern HARD_REG_SET call_used_reg_set;
 415
 416 /* Registers that we don't want to caller save.  */
 417 extern HARD_REG_SET losing_caller_save_reg_set;
 418
 419 /* Indexed by hard register number, contains 1 for registers that are
 420    fixed use -- i.e. in fixed_regs -- or a function value return register
 421    or STRUCT_VALUE_REGNUM or STATIC_CHAIN_REGNUM.  These are the
 422    registers that cannot hold quantities across calls even if we are
 423    willing to save and restore them.  */
 424
 425 extern char call_fixed_regs[FIRST_PSEUDO_REGISTER];
 426
 427 /* The same info as a HARD_REG_SET.  */
 428
 429 extern HARD_REG_SET call_fixed_reg_set;
 430
 431 /* Indexed by hard register number, contains 1 for registers
 432    that are being used for global register decls.
 433    These must be exempt from ordinary flow analysis
 434    and are also considered fixed.  */
 435
 436 extern char global_regs[FIRST_PSEUDO_REGISTER];
 437
 438 /* Contains 1 for registers that are set or clobbered by calls.  */
 439 /* ??? Ideally, this would be just call_used_regs plus global_regs, but
 440    for someone's bright idea to have call_used_regs strictly include
 441    fixed_regs.  Which leaves us guessing as to the set of fixed_regs
 442    that are actually preserved.  We know for sure that those associated
 443    with the local stack frame are safe, but scant others.  */
 444
 445 extern HARD_REG_SET regs_invalidated_by_call;
 446
 447 #ifdef REG_ALLOC_ORDER
 448 /* Table of register numbers in the order in which to try to use them.  */
 449
 450 extern int reg_alloc_order[FIRST_PSEUDO_REGISTER];
 451
 452 /* The inverse of reg_alloc_order.  */
 453
 454 extern int inv_reg_alloc_order[FIRST_PSEUDO_REGISTER];
 455 #endif
 456
 457 /* For each reg class, a HARD_REG_SET saying which registers are in it.  */
 458
 459 extern HARD_REG_SET reg_class_contents[N_REG_CLASSES];
 460
 461 /* For each reg class, number of regs it contains.  */
 462
 463 extern unsigned int reg_class_size[N_REG_CLASSES];
 464
 465 /* For each reg class, table listing all the containing classes.  */
 466
 467 extern enum reg_class reg_class_superclasses[N_REG_CLASSES][N_REG_CLASSES];
 468
 469 /* For each reg class, table listing all the classes contained in it.  */
 470
 471 extern enum reg_class reg_class_subclasses[N_REG_CLASSES][N_REG_CLASSES];
 472
 473 /* For each pair of reg classes,
 474    a largest reg class contained in their union.  */
 475
 476 extern enum reg_class reg_class_subunion[N_REG_CLASSES][N_REG_CLASSES];
 477
 478 /* For each pair of reg classes,
 479    the smallest reg class that contains their union.  */
 480
 481 extern enum reg_class reg_class_superunion[N_REG_CLASSES][N_REG_CLASSES];
 482
 483 /* Number of non-fixed registers.  */
 484
 485 extern int n_non_fixed_regs;
 486
 487 /* Vector indexed by hardware reg giving its name.  */
 488
 489 extern const char * reg_names[FIRST_PSEUDO_REGISTER];
 490
 491 /* Given a hard REGN a FROM mode and a TO mode, return nonzero if
 492    REGN cannot change modes between the specified modes.  */
 493 #define REG_CANNOT_CHANGE_MODE_P(REGN, FROM, TO)                          \
 494          CANNOT_CHANGE_MODE_CLASS (FROM, TO, REGNO_REG_CLASS (REGN))
 495
 496 #endif /* ! GCC_HARD_REG_SET_H */