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/* Binary relations.
Copyright (C) 2002, 2004, 2005 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, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA. */
#include <config.h>
#include "system.h"
#include <bitsetv.h>
#include "getargs.h"
#include "relation.h"
void
relation_print (relation r, relation_node size, FILE *out)
{
relation_node i;
relation_node j;
for (i = 0; i < size; ++i)
{
fprintf (out, "%3lu: ", (unsigned long int) i);
if (r[i])
for (j = 0; r[i][j] != END_NODE; ++j)
fprintf (out, "%3lu ", (unsigned long int) r[i][j]);
fputc ('\n', out);
}
fputc ('\n', out);
}
/*---------------------------------------------------------------.
| digraph & traverse. |
| |
| The following variables are used as common storage between the |
| two. |
`---------------------------------------------------------------*/
static relation R;
static relation_nodes INDEX;
static relation_nodes VERTICES;
static relation_node top;
static relation_node infinity;
static bitsetv F;
static void
traverse (relation_node i)
{
relation_node j;
relation_node height;
VERTICES[++top] = i;
INDEX[i] = height = top;
if (R[i])
for (j = 0; R[i][j] != END_NODE; ++j)
{
if (INDEX[R[i][j]] == 0)
traverse (R[i][j]);
if (INDEX[i] > INDEX[R[i][j]])
INDEX[i] = INDEX[R[i][j]];
bitset_or (F[i], F[i], F[R[i][j]]);
}
if (INDEX[i] == height)
for (;;)
{
j = VERTICES[top--];
INDEX[j] = infinity;
if (i == j)
break;
bitset_copy (F[j], F[i]);
}
}
void
relation_digraph (relation r, relation_node size, bitsetv *function)
{
relation_node i;
infinity = size + 2;
INDEX = xcalloc (size + 1, sizeof *INDEX);
VERTICES = xnmalloc (size + 1, sizeof *VERTICES);
top = 0;
R = r;
F = *function;
for (i = 0; i < size; i++)
if (INDEX[i] == 0 && R[i])
traverse (i);
free (INDEX);
free (VERTICES);
*function = F;
}
/*-------------------------------------------.
| Destructively transpose R_ARG, of size N. |
`-------------------------------------------*/
void
relation_transpose (relation *R_arg, relation_node n)
{
relation r = *R_arg;
/* The result. */
relation new_R = xnmalloc (n, sizeof *new_R);
/* END_R[I] -- next entry of NEW_R[I]. */
relation end_R = xnmalloc (n, sizeof *end_R);
/* NEDGES[I] -- total size of NEW_R[I]. */
size_t *nedges = xcalloc (n, sizeof *nedges);
relation_node i;
relation_node j;
if (trace_flag & trace_sets)
{
fputs ("relation_transpose: input\n", stderr);
relation_print (r, n, stderr);
}
/* Count. */
for (i = 0; i < n; i++)
if (r[i])
for (j = 0; r[i][j] != END_NODE; ++j)
++nedges[r[i][j]];
/* Allocate. */
for (i = 0; i < n; i++)
{
relation_node *sp = NULL;
if (nedges[i] > 0)
{
sp = xnmalloc (nedges[i] + 1, sizeof *sp);
sp[nedges[i]] = END_NODE;
}
new_R[i] = sp;
end_R[i] = sp;
}
/* Store. */
for (i = 0; i < n; i++)
if (r[i])
for (j = 0; r[i][j] != END_NODE; ++j)
*end_R[r[i][j]]++ = i;
free (nedges);
free (end_R);
/* Free the input: it is replaced with the result. */
for (i = 0; i < n; i++)
free (r[i]);
free (r);
if (trace_flag & trace_sets)
{
fputs ("relation_transpose: output\n", stderr);
relation_print (new_R, n, stderr);
}
*R_arg = new_R;
}