gcc/hard-reg-set.h

   1 /* Sets (bit vectors) of hard registers, and operations on them.
   2    Copyright (C) 1987, 1992, 1994 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC
   5
   6 GNU CC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU CC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU CC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20
  21 /* Define the type of a set of hard registers.  */
  22
  23 /* HARD_REG_ELT_TYPE is a typedef of the unsigned integral type which
  24    will be used for hard reg sets, either alone or in an array.
  25
  26    If HARD_REG_SET is a macro, its definition is HARD_REG_ELT_TYPE,
  27    and it has enough bits to represent all the target machine's hard
  28    registers.  Otherwise, it is a typedef for a suitably sized array
  29    of HARD_REG_ELT_TYPEs.  HARD_REG_SET_LONGS is defined as how many.
  30
  31    Note that lots of code assumes that the first part of a regset is
  32    the same format as a HARD_REG_SET.  To help make sure this is true,
  33    we only try the widest integer mode (HOST_WIDE_INT) instead of all the
  34    smaller types.  This approach loses only if there are a very few
  35    registers and then only in the few cases where we have an array of
  36    HARD_REG_SETs, so it needn't be as complex as it used to be.  */
  37
  38 typedef unsigned HOST_WIDE_INT HARD_REG_ELT_TYPE;
  39
  40 #if FIRST_PSEUDO_REGISTER <= HOST_BITS_PER_WIDE_INT
  41
  42 #define HARD_REG_SET HARD_REG_ELT_TYPE
  43
  44 #else
  45
  46 #define HARD_REG_SET_LONGS \
  47  ((FIRST_PSEUDO_REGISTER + HOST_BITS_PER_WIDE_INT - 1)  \
  48   / HOST_BITS_PER_WIDE_INT)
  49 typedef HARD_REG_ELT_TYPE HARD_REG_SET[HARD_REG_SET_LONGS];
  50
  51 #endif
  52
  53 /* HARD_CONST is used to cast a constant to the appropriate type
  54    for use with a HARD_REG_SET.  */
  55
  56 #define HARD_CONST(X) ((HARD_REG_ELT_TYPE) (X))
  57
  58 /* Define macros SET_HARD_REG_BIT, CLEAR_HARD_REG_BIT and TEST_HARD_REG_BIT
  59    to set, clear or test one bit in a hard reg set of type HARD_REG_SET.
  60    All three take two arguments: the set and the register number.
  61
  62    In the case where sets are arrays of longs, the first argument
  63    is actually a pointer to a long.
  64
  65    Define two macros for initializing a set:
  66    CLEAR_HARD_REG_SET and SET_HARD_REG_SET.
  67    These take just one argument.
  68
  69    Also define macros for copying hard reg sets:
  70    COPY_HARD_REG_SET and COMPL_HARD_REG_SET.
  71    These take two arguments TO and FROM; they read from FROM
  72    and store into TO.  COMPL_HARD_REG_SET complements each bit.
  73
  74    Also define macros for combining hard reg sets:
  75    IOR_HARD_REG_SET and AND_HARD_REG_SET.
  76    These take two arguments TO and FROM; they read from FROM
  77    and combine bitwise into TO.  Define also two variants
  78    IOR_COMPL_HARD_REG_SET and AND_COMPL_HARD_REG_SET
  79    which use the complement of the set FROM.
  80
  81    Also define GO_IF_HARD_REG_SUBSET (X, Y, TO):
  82    if X is a subset of Y, go to TO.
  83 */
  84
  85 #ifdef HARD_REG_SET
  86
  87 #define SET_HARD_REG_BIT(SET, BIT)  \
  88  ((SET) |= HARD_CONST (1) << (BIT))
  89 #define CLEAR_HARD_REG_BIT(SET, BIT)  \
  90  ((SET) &= ~(HARD_CONST (1) << (BIT)))
  91 #define TEST_HARD_REG_BIT(SET, BIT)  \
  92  ((SET) & (HARD_CONST (1) << (BIT)))
  93
  94 #define CLEAR_HARD_REG_SET(TO) ((TO) = HARD_CONST (0))
  95 #define SET_HARD_REG_SET(TO) ((TO) = ~ HARD_CONST (0))
  96
  97 #define COPY_HARD_REG_SET(TO, FROM) ((TO) = (FROM))
  98 #define COMPL_HARD_REG_SET(TO, FROM) ((TO) = ~(FROM))
  99
 100 #define IOR_HARD_REG_SET(TO, FROM) ((TO) |= (FROM))
 101 #define IOR_COMPL_HARD_REG_SET(TO, FROM) ((TO) |= ~ (FROM))
 102 #define AND_HARD_REG_SET(TO, FROM) ((TO) &= (FROM))
 103 #define AND_COMPL_HARD_REG_SET(TO, FROM) ((TO) &= ~ (FROM))
 104
 105 #define GO_IF_HARD_REG_SUBSET(X,Y,TO) if (HARD_CONST (0) == ((X) & ~(Y))) goto TO
 106
 107 #define GO_IF_HARD_REG_EQUAL(X,Y,TO) if ((X) == (Y)) goto TO
 108
 109 #else
 110
 111 #define UHOST_BITS_PER_WIDE_INT ((unsigned) HOST_BITS_PER_WIDE_INT)
 112
 113 #define SET_HARD_REG_BIT(SET, BIT)              \
 114   ((SET)[(BIT) / UHOST_BITS_PER_WIDE_INT]       \
 115    |= HARD_CONST (1) << ((BIT) % UHOST_BITS_PER_WIDE_INT))
 116
 117 #define CLEAR_HARD_REG_BIT(SET, BIT)            \
 118   ((SET)[(BIT) / UHOST_BITS_PER_WIDE_INT]       \
 119    &= ~(HARD_CONST (1) << ((BIT) % UHOST_BITS_PER_WIDE_INT)))
 120
 121 #define TEST_HARD_REG_BIT(SET, BIT)             \
 122   ((SET)[(BIT) / UHOST_BITS_PER_WIDE_INT]       \
 123    & (HARD_CONST (1) << ((BIT) % UHOST_BITS_PER_WIDE_INT)))
 124
 125 #define CLEAR_HARD_REG_SET(TO)  \
 126 do { register HARD_REG_ELT_TYPE *scan_tp_ = (TO);               \
 127      register int i;                                            \
 128      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 129        *scan_tp_++ = 0; } while (0)
 130
 131 #define SET_HARD_REG_SET(TO)  \
 132 do { register HARD_REG_ELT_TYPE *scan_tp_ = (TO);               \
 133      register int i;                                            \
 134      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 135        *scan_tp_++ = -1; } while (0)
 136
 137 #define COPY_HARD_REG_SET(TO, FROM)  \
 138 do { register HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM); \
 139      register int i;                                            \
 140      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 141        *scan_tp_++ = *scan_fp_++; } while (0)
 142
 143 #define COMPL_HARD_REG_SET(TO, FROM)  \
 144 do { register HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM); \
 145      register int i;                                            \
 146      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 147        *scan_tp_++ = ~ *scan_fp_++; } while (0)
 148
 149 #define AND_HARD_REG_SET(TO, FROM)  \
 150 do { register HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM); \
 151      register int i;                                            \
 152      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 153        *scan_tp_++ &= *scan_fp_++; } while (0)
 154
 155 #define AND_COMPL_HARD_REG_SET(TO, FROM)  \
 156 do { register HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM); \
 157      register int i;                                            \
 158      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 159        *scan_tp_++ &= ~ *scan_fp_++; } while (0)
 160
 161 #define IOR_HARD_REG_SET(TO, FROM)  \
 162 do { register HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM); \
 163      register int i;                                            \
 164      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 165        *scan_tp_++ |= *scan_fp_++; } while (0)
 166
 167 #define IOR_COMPL_HARD_REG_SET(TO, FROM)  \
 168 do { register HARD_REG_ELT_TYPE *scan_tp_ = (TO), *scan_fp_ = (FROM); \
 169      register int i;                                            \
 170      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 171        *scan_tp_++ |= ~ *scan_fp_++; } while (0)
 172
 173 #define GO_IF_HARD_REG_SUBSET(X,Y,TO)  \
 174 do { register HARD_REG_ELT_TYPE *scan_xp_ = (X), *scan_yp_ = (Y); \
 175      register int i;                                            \
 176      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 177        if (0 != (*scan_xp_++ & ~ *scan_yp_++)) break;           \
 178      if (i == HARD_REG_SET_LONGS) goto TO; } while (0)
 179
 180 #define GO_IF_HARD_REG_EQUAL(X,Y,TO)  \
 181 do { register HARD_REG_ELT_TYPE *scan_xp_ = (X), *scan_yp_ = (Y); \
 182      register int i;                                            \
 183      for (i = 0; i < HARD_REG_SET_LONGS; i++)                   \
 184        if (*scan_xp_++ != *scan_yp_++) break;                   \
 185      if (i == HARD_REG_SET_LONGS) goto TO; } while (0)
 186
 187 #endif
 188
 189 /* Define some standard sets of registers.  */
 190
 191 /* Indexed by hard register number, contains 1 for registers
 192    that are fixed use (stack pointer, pc, frame pointer, etc.).
 193    These are the registers that cannot be used to allocate
 194    a pseudo reg whose life does not cross calls.  */
 195
 196 extern char fixed_regs[FIRST_PSEUDO_REGISTER];
 197
 198 /* The same info as a HARD_REG_SET.  */
 199
 200 extern HARD_REG_SET fixed_reg_set;
 201
 202 /* Indexed by hard register number, contains 1 for registers
 203    that are fixed use or are clobbered by function calls.
 204    These are the registers that cannot be used to allocate
 205    a pseudo reg whose life crosses calls.  */
 206
 207 extern char call_used_regs[FIRST_PSEUDO_REGISTER];
 208
 209 /* The same info as a HARD_REG_SET.  */
 210
 211 extern HARD_REG_SET call_used_reg_set;
 212
 213 /* Indexed by hard register number, contains 1 for registers that are
 214    fixed use -- i.e. in fixed_regs -- or a function value return register
 215    or STRUCT_VALUE_REGNUM or STATIC_CHAIN_REGNUM.  These are the
 216    registers that cannot hold quantities across calls even if we are
 217    willing to save and restore them.  */
 218
 219 extern char call_fixed_regs[FIRST_PSEUDO_REGISTER];
 220
 221 /* The same info as a HARD_REG_SET.  */
 222
 223 extern HARD_REG_SET call_fixed_reg_set;
 224
 225 /* Indexed by hard register number, contains 1 for registers
 226    that are being used for global register decls.
 227    These must be exempt from ordinary flow analysis
 228    and are also considered fixed.  */
 229
 230 extern char global_regs[FIRST_PSEUDO_REGISTER];
 231
 232 /* Table of register numbers in the order in which to try to use them.  */
 233
 234 #ifdef REG_ALLOC_ORDER   /* Avoid undef symbol in certain broken linkers.  */
 235 extern int reg_alloc_order[FIRST_PSEUDO_REGISTER];
 236 #endif
 237
 238 /* For each reg class, a HARD_REG_SET saying which registers are in it.  */
 239
 240 extern HARD_REG_SET reg_class_contents[];
 241
 242 /* For each reg class, number of regs it contains.  */
 243
 244 extern int reg_class_size[N_REG_CLASSES];
 245
 246 /* For each reg class, table listing all the containing classes.  */
 247
 248 extern enum reg_class reg_class_superclasses[N_REG_CLASSES][N_REG_CLASSES];
 249
 250 /* For each reg class, table listing all the classes contained in it.  */
 251
 252 extern enum reg_class reg_class_subclasses[N_REG_CLASSES][N_REG_CLASSES];
 253
 254 /* For each pair of reg classes,
 255    a largest reg class contained in their union.  */
 256
 257 extern enum reg_class reg_class_subunion[N_REG_CLASSES][N_REG_CLASSES];
 258
 259 /* For each pair of reg classes,
 260    the smallest reg class that contains their union.  */
 261
 262 extern enum reg_class reg_class_superunion[N_REG_CLASSES][N_REG_CLASSES];
 263
 264 /* Number of non-fixed registers.  */
 265
 266 extern int n_non_fixed_regs;
 267
 268 /* Vector indexed by hardware reg giving its name.  */
 269
 270 extern char *reg_names[FIRST_PSEUDO_REGISTER];