14-fyi-closure-bitset.patch

[Akim Demaille]

Index: ChangeLog
from  Akim Demaille  <address@hidden>
        
        * src/closure.c (firsts): Now, also a bitset.
        Adjust all dependencies.
        (varsetsize): Remove, now unused.
        * src/warshall.h, src/warshall.c: Now work on arrays of bitsets.
        
Index: src/closure.c
--- src/closure.c Mon, 04 Feb 2002 18:06:05 +0100 akim
+++ src/closure.c Fri, 01 Mar 2002 14:00:24 +0100 akim
@@ -25,8 +25,8 @@
 #include "reader.h"
 #include "closure.h"
 #include "derives.h"
-#include "warshall.h"
 #include "bitset.h"
+#include "warshall.h"
 
 /* NITEMSET is the size of the array ITEMSET.  */
 short *itemset;
@@ -35,15 +35,12 @@
 static bitset ruleset;
 
 /* internal data.  See comments before set_fderives and set_firsts.  */
-static bitset *fderives;
-static unsigned int *firsts;
+static bitset *fderives = NULL;
+static bitset *firsts = NULL;
 
 /* Retrieve the FDERIVES/FIRSTS sets of the nonterminals numbered Var.  */
 #define FDERIVES(Var)   fderives[(Var) - ntokens]
-#define   FIRSTS(Var)   (firsts   + ((Var) - ntokens) * varsetsize)
-
-/* number of words required to hold a bit for each variable */
-static int varsetsize;
+#define   FIRSTS(Var)   firsts[(Var) - ntokens]
 
 
 /*-----------------.
@@ -77,7 +74,7 @@
     {
       fprintf (stderr, "\t%s firsts\n", symbols[i]->tag);
       for (j = 0; j < nvars; j++)
-       if (BITISSET (FIRSTS (i), j))
+       if (bitset_test (FIRSTS (i), j))
          fprintf (stderr, "\t\t%d (%s)\n",
                   j + ntokens, symbols[j + ntokens]->tag);
     }
@@ -88,11 +85,9 @@
 static void
 print_fderives (void)
 {
-  int i;
-  int j;
+  int i, j;
 
   fprintf (stderr, "FDERIVES\n");
-
   for (i = ntokens; i < nsyms; i++)
     {
       fprintf (stderr, "\t%s derives\n", symbols[i]->tag);
@@ -109,32 +104,34 @@
   fprintf (stderr, "\n\n");
 }
 
-/*-------------------------------------------------------------------.
-| Set FIRSTS to be an NVARS by NVARS bit matrix indicating which     |
-| items can represent the beginning of the input corresponding to    |
-| which other items.                                                 |
-|                                                                    |
-| For example, if some rule expands symbol 5 into the sequence of    |
-| symbols 8 3 20, the symbol 8 can be the beginning of the data for  |
-| symbol 5, so the bit [8 - ntokens, 5 - ntokens] in firsts is set.  |
-`-------------------------------------------------------------------*/
+/*------------------------------------------------------------------.
+| Set FIRSTS to be an NVARS array of NVARS bitsets indicating which |
+| items can represent the beginning of the input corresponding to   |
+| which other items.                                                |
+|                                                                   |
+| For example, if some rule expands symbol 5 into the sequence of   |
+| symbols 8 3 20, the symbol 8 can be the beginning of the data for |
+| symbol 5, so the bit [8 - ntokens] in first[5 - ntokens] (= FIRST |
+| (5)) is set.                                                      |
+`------------------------------------------------------------------*/
 
 static void
 set_firsts (void)
 {
   int i, j;
 
-  varsetsize = WORDSIZE (nvars);
-
-  firsts = XCALLOC (unsigned, nvars * varsetsize);
-
+  firsts = XCALLOC (bitset, nvars);
   for (i = ntokens; i < nsyms; i++)
-    for (j = 0; derives[i][j] >= 0; ++j)
-      {
-       int symbol = ritem[rules[derives[i][j]].rhs];
-       if (ISVAR (symbol))
-         SETBIT (FIRSTS (i), symbol - ntokens);
-      }
+    {
+      FIRSTS (i) = bitset_create (nvars, BITSET_FIXED);
+      bitset_zero (FIRSTS (i));
+      for (j = 0; derives[i][j] >= 0; ++j)
+       {
+         int symbol = ritem[rules[derives[i][j]].rhs];
+         if (ISVAR (symbol))
+           bitset_set (FIRSTS (i), symbol - ntokens);
+       }
+    }
 
   RTC (firsts, nvars);
 
@@ -169,13 +166,15 @@
 
   for (i = ntokens; i < nsyms; ++i)
     for (j = ntokens; j < nsyms; ++j)
-      if (BITISSET (FIRSTS (i), j - ntokens))
+      if (bitset_test (FIRSTS (i), j - ntokens))
        for (k = 0; derives[j][k] > 0; ++k)
          bitset_set (FDERIVES (i), derives[j][k]);
 
   if (trace_flag)
     print_fderives ();
 
+  for (i = ntokens; i < nsyms; ++i)
+    bitset_free (FIRSTS (i));
   XFREE (firsts);
 }
 
Index: src/warshall.c
--- src/warshall.c Thu, 13 Dec 2001 10:51:57 +0100 akim
+++ src/warshall.c Fri, 01 Mar 2002 13:55:31 +0100 akim
@@ -1,5 +1,5 @@
 /* Generate transitive closure of a matrix,
-   Copyright 1984, 1989, 2000, 2001 Free Software Foundation, Inc.
+   Copyright 1984, 1989, 2000, 2001, 2002 Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
@@ -21,19 +21,17 @@
 
 #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
-bitmatrix_print (const char *title, unsigned *matrix, size_t size)
+bitmatrix_print (const char *title, bitset *matrix, size_t size)
 {
   size_t i, j;
-  size_t rowsize = WORDSIZE (size) * sizeof (unsigned);
-#define ROW(Num) ((unsigned *) ((char *) matrix + ((Num) * rowsize)))
 
   /* Title. */
   fprintf (stderr, "%s BEGIN\n", title);
@@ -59,7 +57,7 @@
     {
       fprintf (stderr, "%2d|", i);
       for (j = 0; j < size; ++j)
-       fputs (BITISSET (ROW (i), j) ? "1" : " ", stderr);
+       fputs (bitset_test (matrix[i], j) ? "1" : " ", stderr);
       fputs ("|\n", stderr);
     }
 
@@ -73,44 +71,45 @@
   fprintf (stderr, "%s END\n\n", title);
 }
 
-#define R(Num) (unsigned *) ((char *) R + ((Num) * rowsize))
+/*-------------------------------------------------------------------.
+| Given the MATRIX array of N bitsets of size N, modify its contents |
+| to be the transive closure of what was given.                      |
+`-------------------------------------------------------------------*/
 
 static void
-TC (unsigned *R, int n)
+TC (bitset *matrix, int n)
 {
-  int rowsize = WORDSIZE (n) * sizeof (unsigned);
   int i, j, k;
 
   if (trace_flag)
-    bitmatrix_print ("TC: Input", R, n);
+    bitmatrix_print ("TC: Input", matrix, n);
 
   /* R (J, I) && R (I, K) => R (J, K).
      I *must* be the outter loop. */
 
   for (i = 0; i < n; ++i)
     for (j = 0; j < n; ++j)
-      if (BITISSET (R (j), i))
+      if (bitset_test (matrix[j], i))
        for (k = 0; k < n; ++k)
-         if (BITISSET (R (i), k))
-           SETBIT (R (j), k);
+         if (bitset_test (matrix[i], k))
+           bitset_set (matrix[j], k);
 
   if (trace_flag)
-    bitmatrix_print ("TC: Output", R, n);
+    bitmatrix_print ("TC: Output", matrix, n);
 }
 
 
 /*---------------------------------------------------------------.
 | Reflexive Transitive Closure.  Same as TC and then set all the |
-| bits on the diagonal of R.                                     |
+| bits on the diagonal of MATRIX.                                |
 `---------------------------------------------------------------*/
 
 void
-RTC (unsigned *R, int n)
+RTC (bitset *matrix, int n)
 {
-  int rowsize = WORDSIZE (n) * sizeof (unsigned);
   int i;
 
-  TC (R, n);
+  TC (matrix, n);
   for (i = 0; i < n; ++i)
-    SETBIT (R (i), i);
+    bitset_set (matrix[i], i);
 }
Index: src/warshall.h
--- src/warshall.h Mon, 03 Dec 2001 20:11:46 +0100 akim
+++ src/warshall.h Fri, 01 Mar 2002 13:50:55 +0100 akim
@@ -1,5 +1,5 @@
 /* Generate transitive closure of a matrix,
-   Copyright 1984, 1989, 2000, 2001 Free Software Foundation, Inc.
+   Copyright 1984, 1989, 2000, 2001, 2002 Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
@@ -21,5 +21,5 @@
 #ifndef WARSHALL_H_
 # define WARSHALL_H_
 
-void RTC PARAMS ((unsigned *, int));
+void RTC PARAMS ((bitset *, int));
 #endif /* !WARSHALL_H_ */