* src/closure.c (firsts): Now, also a bitset.

[bison.git] / src / warshall.c

diff --git a/src/warshall.c b/src/warshall.c
index 9afd7fd9ff0b705f8c74a7d4b7037712f207eb21..ff41d5ba9ddefd398b0392ddac9f8f381eaf4f69 100644 (file)
--- a/src/warshall.c
+++ b/src/warshall.c
@@ -1,5 +1,5 @@
 /* Generate transitive closure of a matrix,
-   Copyright (C) 1984, 1989, 2000 Free Software Foundation, Inc.
+   Copyright 1984, 1989, 2000, 2001, 2002 Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
@@ -20,95 +20,96 @@
 
 
 #include "system.h"
+#include "getargs.h"
+#include "bitset.h"
 #include "warshall.h"
 
-/* Given n by n matrix of bits R, modify its contents to be the
-   transive closure of what was given.  */
+/*--------------------------------------------------------.
+| Display the MATRIX array of SIZE bitsets of size SIZE.  |
+`--------------------------------------------------------*/
 
 static void
-TC (unsigned *R, int n)
+bitmatrix_print (const char *title, bitset *matrix, size_t size)
 {
-  int rowsize;
-  unsigned mask;
-  unsigned *rowj;
-  unsigned *rp;
-  unsigned *rend;
-  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)
+  size_t i, j;
+
+  /* Title. */
+  fprintf (stderr, "%s BEGIN\n", title);
+
+  /* Column numbers. */
+  fputs ("   ", stderr);
+  for (i = 0; i < size; ++i)
+    putc (i / 10 ? '0' + i / 10 : ' ', stderr);
+  putc ('\n', stderr);
+  fputs ("   ", stderr);
+  for (i = 0; i < size; ++i)
+    fprintf (stderr, "%d", i % 10);
+  putc ('\n', stderr);
+
+  /* Bar. */
+  fputs ("  .", stderr);
+  for (i = 0; i < size; ++i)
+    putc ('-', stderr);
+  fputs (".\n", stderr);
+
+  /* Contents. */
+  for (i = 0; i < size; ++i)
     {
-      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);
+      fprintf (stderr, "%2d|", i);
+      for (j = 0; j < size; ++j)
+       fputs (bitset_test (matrix[i], j) ? "1" : " ", stderr);
+      fputs ("|\n", stderr);
     }
-}
 
+  /* Bar. */
+  fputs ("  `", stderr);
+  for (i = 0; i < size; ++i)
+    putc ('-', stderr);
+  fputs ("'\n", stderr);
+
+  /* End title. */
+  fprintf (stderr, "%s END\n\n", title);
+}
 
-/* Reflexive Transitive Closure.  Same as TC
-   and then set all the bits on the diagonal of R.  */
+/*-------------------------------------------------------------------.
+| Given the MATRIX array of N bitsets of size N, modify its contents |
+| to be the transive closure of what was given.                      |
+`-------------------------------------------------------------------*/
 
-void
-RTC (unsigned *R, int n)
+static void
+TC (bitset *matrix, int n)
 {
-  int rowsize;
-  unsigned mask;
-  unsigned *rp;
-  unsigned *relend;
+  int i, j, k;
 
-  TC(R, n);
+  if (trace_flag)
+    bitmatrix_print ("TC: Input", matrix, n);
 
-  rowsize = WORDSIZE(n) * sizeof(unsigned);
-  relend = (unsigned *) ((char *) R + n*rowsize);
+  /* R (J, I) && R (I, K) => R (J, K).
+     I *must* be the outter loop. */
 
-  mask = 1;
-  rp = R;
-  while (rp < relend)
-    {
-      *rp |= mask;
+  for (i = 0; i < n; ++i)
+    for (j = 0; j < n; ++j)
+      if (bitset_test (matrix[j], i))
+       for (k = 0; k < n; ++k)
+         if (bitset_test (matrix[i], k))
+           bitset_set (matrix[j], k);
 
-      mask <<= 1;
-      if (mask == 0)
-       {
-         mask = 1;
-         rp++;
-       }
+  if (trace_flag)
+    bitmatrix_print ("TC: Output", matrix, n);
+}
 
-      rp = (unsigned *) ((char *) rp + rowsize);
-    }
+
+/*---------------------------------------------------------------.
+| Reflexive Transitive Closure.  Same as TC and then set all the |
+| bits on the diagonal of MATRIX.                                |
+`---------------------------------------------------------------*/
+
+void
+RTC (bitset *matrix, int n)
+{
+  int i;
+
+  TC (matrix, n);
+  for (i = 0; i < n; ++i)
+    bitset_set (matrix[i], i);
 }