gcc/sparseset.h

   1 /* SparseSet implementation.
   2    Copyright (C) 2007 Free Software Foundation, Inc.
   3    Contributed by Peter Bergner <bergner@vnet.ibm.com>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef GCC_SPARSESET_H
  22 #define GCC_SPARSESET_H
  23
  24 #include <assert.h>
  25
  26 #define SPARSESET_ELT_BITS ((unsigned) HOST_BITS_PER_WIDEST_FAST_INT)
  27 #define SPARSESET_ELT_TYPE unsigned int
  28
  29 /* Data Structure used for the SparseSet representation.  */
  30
  31 typedef struct sparseset_def
  32 {
  33   SPARSESET_ELT_TYPE *dense;    /* Dense array.  */
  34   SPARSESET_ELT_TYPE *sparse;   /* Sparse array.  */
  35   SPARSESET_ELT_TYPE members;   /* Number of elements.  */
  36   SPARSESET_ELT_TYPE size;      /* Maximum number of elements.  */
  37   SPARSESET_ELT_TYPE iter;      /* Iterator index.  */
  38   unsigned char iter_inc;       /* Iteration increment amount.  */
  39   bool iterating;
  40   SPARSESET_ELT_TYPE elms[2];   /* Combined dense and sparse arrays.  */
  41 } *sparseset;
  42
  43 #define sparseset_free(MAP)  free(MAP)
  44 extern sparseset sparseset_alloc (SPARSESET_ELT_TYPE n_elms);
  45 extern void sparseset_clear_bit (sparseset, SPARSESET_ELT_TYPE);
  46 extern void sparseset_copy (sparseset, sparseset);
  47 extern void sparseset_and (sparseset, sparseset, sparseset);
  48 extern void sparseset_and_compl (sparseset, sparseset, sparseset);
  49 extern void sparseset_ior (sparseset, sparseset, sparseset);
  50 extern bool sparseset_equal_p (sparseset, sparseset);
  51
  52 /* Operation: S = {}
  53    Clear the set of all elements.  */
  54
  55 static inline void
  56 sparseset_clear (sparseset s)
  57 {
  58   s->members = 0;
  59   s->iterating = false;
  60 }
  61
  62 /* Return the number of elements currently in the set.  */
  63
  64 static inline SPARSESET_ELT_TYPE
  65 sparseset_cardinality (sparseset s)
  66 {
  67   return s->members;
  68 }
  69
  70 /* Return the maximum number of elements this set can hold.  */
  71
  72 static inline SPARSESET_ELT_TYPE
  73 sparseset_size (sparseset s)
  74 {
  75   return s->size;
  76 }
  77
  78 /* Return true if e is a member of the set S, otherwise return false.  */
  79
  80 static inline bool
  81 sparseset_bit_p (sparseset s, SPARSESET_ELT_TYPE e)
  82 {
  83   SPARSESET_ELT_TYPE idx;
  84
  85   gcc_assert (e < s->size);
  86
  87   idx = s->sparse[e];
  88
  89   return idx < s->members && s->dense[idx] == e;
  90 }
  91
  92 /* Low level insertion routine not meant for use outside of sparseset.[ch].
  93    Assumes E is valid and not already a member of the set S.  */
  94
  95 static inline void
  96 sparseset_insert_bit (sparseset s, SPARSESET_ELT_TYPE e, SPARSESET_ELT_TYPE idx)
  97 {
  98   s->sparse[e] = idx;
  99   s->dense[idx] = e;
 100 }
 101
 102 /* Operation: S = S + {e}
 103    Insert E into the set S, if it isn't already a member.  */
 104
 105 static inline void
 106 sparseset_set_bit (sparseset s, SPARSESET_ELT_TYPE e)
 107 {
 108   if (!sparseset_bit_p (s, e))
 109     sparseset_insert_bit (s, e, s->members++);
 110 }
 111
 112 /* Return and remove an arbitrary element from the set S.  */
 113
 114 static inline SPARSESET_ELT_TYPE
 115 sparseset_pop (sparseset s)
 116 {
 117   SPARSESET_ELT_TYPE mem = s->members;
 118
 119   gcc_assert (mem != 0);
 120
 121   s->members = mem - 1;
 122   return s->dense[mem];
 123 }
 124
 125 static inline void
 126 sparseset_iter_init (sparseset s)
 127 {
 128   s->iter = 0;
 129   s->iter_inc = 1;
 130   s->iterating = true;
 131 }
 132
 133 static inline bool
 134 sparseset_iter_p (sparseset s)
 135 {
 136   if (s->iterating && s->iter < s->members)
 137     return true;
 138   else
 139     return s->iterating = false;
 140 }
 141
 142 static inline SPARSESET_ELT_TYPE
 143 sparseset_iter_elm (sparseset s)
 144 {
 145   return s->dense[s->iter];
 146 }
 147
 148 static inline void
 149 sparseset_iter_next (sparseset s)
 150 {
 151   s->iter += s->iter_inc;
 152   s->iter_inc = 1;
 153 }
 154
 155 #define EXECUTE_IF_SET_IN_SPARSESET(SPARSESET, ITER)                    \
 156   for (sparseset_iter_init (SPARSESET);                                 \
 157        sparseset_iter_p (SPARSESET)                                     \
 158        && (((ITER) = sparseset_iter_elm (SPARSESET)) || 1);             \
 159        sparseset_iter_next (SPARSESET))
 160
 161 #endif /* GCC_SPARSESET_H */