text: /* SparseSet implementation.
     Copyright (C) 2007 Free Software Foundation, Inc.
     Contributed by Peter Bergner <bergner@vnet.ibm.com>
  
  This file is part of GCC.
  
  GCC is free software; you can redistribute it and/or modify it under
  the terms of the GNU General Public License as published by the Free
  Software Foundation; either version 3, or (at your option) any later
  version.
  
  GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  for more details.
  
  You should have received a copy of the GNU General Public License
  along with GCC; see the file COPYING3.  If not see
  <http://www.gnu.org/licenses/>.  */
  
  #ifndef GCC_SPARSESET_H
  #define GCC_SPARSESET_H
  
  #include <assert.h>
  
  #define SPARSESET_ELT_BITS ((unsigned) HOST_BITS_PER_WIDEST_FAST_INT)
  #define SPARSESET_ELT_TYPE unsigned int
  
  /* Data Structure used for the SparseSet representation.  */
  
  typedef struct sparseset_def
  {
    SPARSESET_ELT_TYPE *dense;	/* Dense array.  */
    SPARSESET_ELT_TYPE *sparse;	/* Sparse array.  */
    SPARSESET_ELT_TYPE members;	/* Number of elements.  */
    SPARSESET_ELT_TYPE size;	/* Maximum number of elements.  */
    SPARSESET_ELT_TYPE iter;	/* Iterator index.  */
    unsigned char iter_inc;	/* Iteration increment amount.  */
    bool iterating;
    SPARSESET_ELT_TYPE elms[2];   /* Combined dense and sparse arrays.  */
  } *sparseset;
  
  #define sparseset_free(MAP)  free(MAP)
  extern sparseset sparseset_alloc (SPARSESET_ELT_TYPE n_elms);
  extern void sparseset_clear_bit (sparseset, SPARSESET_ELT_TYPE);
  extern void sparseset_copy (sparseset, sparseset);
  extern void sparseset_and (sparseset, sparseset, sparseset);
  extern void sparseset_and_compl (sparseset, sparseset, sparseset);
  extern void sparseset_ior (sparseset, sparseset, sparseset);
  extern bool sparseset_equal_p (sparseset, sparseset);
  
  /* Operation: S = {}
     Clear the set of all elements.  */
  
  static inline void
  sparseset_clear (sparseset s)
  {
    s->members = 0;
    s->iterating = false;
  }
  
  /* Return the number of elements currently in the set.  */
  
  static inline SPARSESET_ELT_TYPE
  sparseset_cardinality (sparseset s)
  {
    return s->members;
  }
  
  /* Return the maximum number of elements this set can hold.  */
  
  static inline SPARSESET_ELT_TYPE
  sparseset_size (sparseset s)
  {
    return s->size;
  }
  
  /* Return true if e is a member of the set S, otherwise return false.  */
  
  static inline bool
  sparseset_bit_p (sparseset s, SPARSESET_ELT_TYPE e)
  {
    SPARSESET_ELT_TYPE idx;
  
    gcc_assert (e < s->size);
  
    idx = s->sparse[e];
  
    return idx < s->members && s->dense[idx] == e;
  }
  
  /* Low level insertion routine not meant for use outside of sparseset.[ch].
     Assumes E is valid and not already a member of the set S.  */
  
  static inline void
  sparseset_insert_bit (sparseset s, SPARSESET_ELT_TYPE e, SPARSESET_ELT_TYPE idx)
  {
    s->sparse[e] = idx;
    s->dense[idx] = e;
  }
  
  /* Operation: S = S + {e}
     Insert E into the set S, if it isn't already a member.  */
  
  static inline void
  sparseset_set_bit (sparseset s, SPARSESET_ELT_TYPE e)
  {
    if (!sparseset_bit_p (s, e))
      sparseset_insert_bit (s, e, s->members++);
  }
  
  /* Return and remove an arbitrary element from the set S.  */
  
  static inline SPARSESET_ELT_TYPE
  sparseset_pop (sparseset s)
  {
    SPARSESET_ELT_TYPE mem = s->members;
  
    gcc_assert (mem != 0);
  
    s->members = mem - 1;
    return s->dense[mem];
  }
  
  static inline void
  sparseset_iter_init (sparseset s)
  {
    s->iter = 0;
    s->iter_inc = 1;
    s->iterating = true;
  }
  
  static inline bool
  sparseset_iter_p (sparseset s)
  {
    if (s->iterating && s->iter < s->members)
      return true;
    else
      return s->iterating = false;
  }
  
  static inline SPARSESET_ELT_TYPE
  sparseset_iter_elm (sparseset s)
  {
    return s->dense[s->iter];
  }
  
  static inline void
  sparseset_iter_next (sparseset s)
  {
    s->iter += s->iter_inc;
    s->iter_inc = 1;
  }
  
  #define EXECUTE_IF_SET_IN_SPARSESET(SPARSESET, ITER)			\
    for (sparseset_iter_init (SPARSESET);					\
         sparseset_iter_p (SPARSESET)					\
         && (((ITER) = sparseset_iter_elm (SPARSESET)) || 1);		\
         sparseset_iter_next (SPARSESET))
  
  #endif /* GCC_SPARSESET_H */
  