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      1 /* A simple, memory-efficient bitset implementation.
      2 
      3    Copyright (C) 2009-2012 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 #include <config.h>
     21 #include "system.h"
     22 
     23 #include "Sbitset.h"
     24 
     25 Sbitset
     26 Sbitset__new (Sbitset__Index nbits)
     27 {
     28   /* Some functions, like Sbitset__last_byte_mask, will fail if nbits = 0.  */
     29   aver (nbits);
     30   return xcalloc (1, Sbitset__nbytes (nbits));
     31 }
     32 
     33 Sbitset
     34 Sbitset__new_on_obstack (Sbitset__Index nbits, struct obstack *obstackp)
     35 {
     36   Sbitset result;
     37   Sbitset ptr;
     38   Sbitset end;
     39   aver (nbits);
     40   result = obstack_alloc (obstackp, Sbitset__nbytes (nbits));
     41   for (ptr = result, end = result + Sbitset__nbytes (nbits); ptr < end; ++ptr)
     42     *ptr = 0;
     43   return result;
     44 }
     45 
     46 void
     47 Sbitset__delete (Sbitset self)
     48 {
     49   free (self);
     50 }
     51 
     52 bool
     53 Sbitset__isEmpty (Sbitset self, Sbitset__Index nbits)
     54 {
     55   Sbitset last = self + Sbitset__nbytes (nbits) - 1;
     56   for (; self < last; ++self)
     57     if (*self != 0)
     58       return false;
     59   return ((*last) & Sbitset__last_byte_mask (nbits)) == 0;
     60 }
     61 
     62 void
     63 Sbitset__fprint(Sbitset self, Sbitset__Index nbits, FILE *file)
     64 {
     65   Sbitset__Index i;
     66   Sbitset itr;
     67   bool first = true;
     68   fprintf (file,
     69            "nbits = %" SBITSET__INDEX__CONVERSION_SPEC ", set = {",
     70            nbits);
     71   SBITSET__FOR_EACH (self, nbits, itr, i)
     72     {
     73       if (first)
     74         first = false;
     75       else
     76         fprintf (file, ",");
     77       fprintf (file, " %" SBITSET__INDEX__CONVERSION_SPEC, i);
     78     }
     79   fprintf (file, " }");
     80 }
     81