src/Sbitset.h

   1 /* A simple, memory-efficient bitset implementation.
   2
   3    Copyright (C) 2009 Free Software Foundation, Inc.
   4
   5    This file is part of Bison, the GNU Compiler Compiler.
   6
   7    This program is free software: you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation, either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef SBITSET_H_
  21 # define SBITSET_H_
  22
  23 typedef char *Sbitset;
  24 typedef size_t Sbitset__Index;
  25
  26 #define Sbitset__nbytes(NBITS)            (((NBITS)+7)/8)
  27 #define Sbitset__byteAddress(SELF, INDEX) (((SELF) + (INDEX)/8))
  28 #define Sbitset__bit_mask(INDEX)          (0x1 << (7 - (INDEX)%8))
  29 #define Sbitset__last_byte_mask(NBITS)    (0xff << (7 - ((NBITS)-1)%8))
  30
  31 /* nbits must not be 0.  */
  32 Sbitset Sbitset__new (Sbitset__Index nbits);
  33 Sbitset Sbitset__new_on_obstack (Sbitset__Index nbits,
  34                                  struct obstack *obstackp);
  35 void Sbitset__delete (Sbitset self);
  36
  37 #define Sbitset__test(SELF, INDEX)                                            \
  38   ((*Sbitset__byteAddress ((SELF), (INDEX)) & Sbitset__bit_mask (INDEX)) != 0)
  39
  40 bool Sbitset__isEmpty (Sbitset self, Sbitset__Index nbits);
  41
  42 void Sbitset__fprint(Sbitset self, Sbitset__Index nbits, FILE *file);
  43
  44 #define Sbitset__set(SELF, INDEX)                                             \
  45 do {                                                                          \
  46   *Sbitset__byteAddress ((SELF), (INDEX)) =                                   \
  47     *Sbitset__byteAddress ((SELF), (INDEX)) | Sbitset__bit_mask (INDEX);      \
  48 } while(0)
  49
  50 #define Sbitset__reset(SELF, INDEX)                                           \
  51 do {                                                                          \
  52   *Sbitset__byteAddress ((SELF), (INDEX)) =                                   \
  53     *Sbitset__byteAddress ((SELF), (INDEX)) & ~Sbitset__bit_mask (INDEX);     \
  54 } while(0)
  55
  56 /* NBITS is the size of the bitset.  More than NBITS bits might be reset.  */
  57 #define Sbitset__zero(SELF, NBITS)                                            \
  58 do {                                                                          \
  59   memset (SELF, 0, Sbitset__nbytes (NBITS));                                  \
  60 } while(0)
  61
  62 /* NBITS is the size of the bitset.  More than NBITS bits might be set.  */
  63 #define Sbitset__ones(SELF, NBITS)                                            \
  64 do {                                                                          \
  65   memset (SELF, 0xff, Sbitset__nbytes (NBITS));                               \
  66 } while(0)
  67
  68 /* NBITS is the size of every bitset.  More than NBITS bits might be set.  */
  69 #define Sbitset__or(SELF, OTHER1, OTHER2, NBITS)                              \
  70 do {                                                                          \
  71   char *ptr_self = (SELF);                                                    \
  72   char *ptr_other1 = (OTHER1);                                                \
  73   char *ptr_other2 = (OTHER2);                                                \
  74   char *end_self = ptr_self + Sbitset__nbytes (NBITS);                        \
  75   for (; ptr_self < end_self; ++ptr_self, ++ptr_other1, ++ptr_other2)         \
  76     *ptr_self = *ptr_other1 | *ptr_other2;                                    \
  77 } while(0)
  78
  79 #define SBITSET__FOR_EACH(SELF, NBITS, ITER, INDEX)                           \
  80   for ((ITER) = (SELF); (ITER) < (SELF) + Sbitset__nbytes (NBITS); ++(ITER))  \
  81     if (*(ITER) != 0)                                                         \
  82       for ((INDEX) = ((ITER)-(SELF))*8;                                       \
  83            (INDEX) < (NBITS) && (SELF)+(INDEX)/8 < (ITER)+1;                  \
  84            ++(INDEX))                                                         \
  85         if (((*ITER) & Sbitset__bit_mask (INDEX)) != 0)
  86
  87 #endif /* !SBITSET_H_ */