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115 lines
2.3 KiB
C
115 lines
2.3 KiB
C
/* Generate transitive closure of a matrix,
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Copyright 1984, 1989, 2000 Free Software Foundation, Inc.
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This file is part of Bison, the GNU Compiler Compiler.
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Bison is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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Bison is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with Bison; see the file COPYING. If not, write to
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the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "system.h"
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#include "warshall.h"
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/* Given n by n matrix of bits R, modify its contents to be the
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transive closure of what was given. */
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static void
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TC (unsigned *R, int n)
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{
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int rowsize;
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unsigned mask;
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unsigned *rowj;
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unsigned *rp;
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unsigned *rend;
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unsigned *ccol;
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unsigned *relend;
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unsigned *cword;
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unsigned *rowi;
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rowsize = WORDSIZE(n) * sizeof(unsigned);
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relend = (unsigned *) ((char *) R + (n * rowsize));
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cword = R;
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mask = 1;
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rowi = R;
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while (rowi < relend)
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{
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ccol = cword;
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rowj = R;
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while (rowj < relend)
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{
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if (*ccol & mask)
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{
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rp = rowi;
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rend = (unsigned *) ((char *) rowj + rowsize);
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while (rowj < rend)
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*rowj++ |= *rp++;
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}
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else
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{
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rowj = (unsigned *) ((char *) rowj + rowsize);
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}
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ccol = (unsigned *) ((char *) ccol + rowsize);
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}
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mask <<= 1;
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if (mask == 0)
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{
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mask = 1;
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cword++;
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}
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rowi = (unsigned *) ((char *) rowi + rowsize);
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}
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}
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/* Reflexive Transitive Closure. Same as TC
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and then set all the bits on the diagonal of R. */
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void
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RTC (unsigned *R, int n)
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{
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int rowsize;
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unsigned mask;
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unsigned *rp;
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unsigned *relend;
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TC(R, n);
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rowsize = WORDSIZE(n) * sizeof(unsigned);
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relend = (unsigned *) ((char *) R + n*rowsize);
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mask = 1;
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rp = R;
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while (rp < relend)
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{
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*rp |= mask;
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mask <<= 1;
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if (mask == 0)
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{
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mask = 1;
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rp++;
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}
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rp = (unsigned *) ((char *) rp + rowsize);
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}
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}
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