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/* Generate transitive closure of a matrix, 
   Copyright (C) 1984, 1989 Free Software Foundation, Inc. 
 
This file is part of Bison, the GNU Compiler Compiler. 
 
Bison 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 2, or (at your option) 
any later version. 
 
Bison 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 Bison; see the file COPYING.  If not, write to 
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */ 
 
 
#include  
#include "system.h" 
#include "machine.h" 
 
 
/* given n by n matrix of bits R, modify its contents 
   to be the transive closure of what was given.  */ 
 
void 
TC(R, n) 
unsigned *R; 
int n; 
{ 
  register int rowsize; 
  register unsigned mask; 
  register unsigned *rowj; 
  register unsigned *rp; 
  register unsigned *rend; 
  register unsigned *ccol; 
 
  unsigned *relend; 
  unsigned *cword; 
  unsigned *rowi; 
 
  rowsize = WORDSIZE(n) * sizeof(unsigned); 
  relend = (unsigned *) ((char *) R + (n * rowsize)); 
 
  cword = R; 
  mask = 1; 
  rowi = R; 
  while (rowi < relend) 
    { 
      ccol = cword; 
      rowj = R; 
 
      while (rowj < relend) 
	{ 
	  if (*ccol & mask) 
	    { 
	      rp = rowi; 
	      rend = (unsigned *) ((char *) rowj + rowsize); 
 
	      while (rowj < rend) 
		*rowj++ |= *rp++; 
	    } 
	  else 
	    { 
	      rowj = (unsigned *) ((char *) rowj + rowsize); 
	    } 
 
	  ccol = (unsigned *) ((char *) ccol + rowsize); 
	} 
 
      mask <<= 1; 
      if (mask == 0) 
	{ 
	  mask = 1; 
	  cword++; 
	} 
 
      rowi = (unsigned *) ((char *) rowi + rowsize); 
    } 
} 
 
 
/* Reflexive Transitive Closure.  Same as TC 
   and then set all the bits on the diagonal of R.  */ 
 
void 
RTC(R, n) 
unsigned *R; 
int n; 
{ 
  register int rowsize; 
  register unsigned mask; 
  register unsigned *rp; 
  register unsigned *relend; 
 
  TC(R, n); 
 
  rowsize = WORDSIZE(n) * sizeof(unsigned); 
  relend = (unsigned *) ((char *) R + n*rowsize); 
 
  mask = 1; 
  rp = R; 
  while (rp < relend) 
    { 
      *rp |= mask; 
 
      mask <<= 1; 
      if (mask == 0) 
	{ 
	  mask = 1; 
	  rp++; 
	} 
 
      rp = (unsigned *) ((char *) rp + rowsize); 
    } 
}