distr/cudd/cuddSign.c

   1 /**CFile***********************************************************************
   2
   3   FileName    [cuddSign.c]
   4
   5   PackageName [cudd]
   6
   7   Synopsis    [Computation of signatures.]
   8
   9   Description [External procedures included in this module:
  10                     <ul>
  11                     <li> Cudd_CofMinterm();
  12                     </ul>
  13                 Static procedures included in this module:
  14                     <ul>
  15                     <li> ddCofMintermAux()
  16                     </ul>
  17                     ]
  18
  19   Author      [Fabio Somenzi]
  20
  21   Copyright   [Copyright (c) 1995-2004, Regents of the University of Colorado
  22
  23   All rights reserved.
  24
  25   Redistribution and use in source and binary forms, with or without
  26   modification, are permitted provided that the following conditions
  27   are met:
  28
  29   Redistributions of source code must retain the above copyright
  30   notice, this list of conditions and the following disclaimer.
  31
  32   Redistributions in binary form must reproduce the above copyright
  33   notice, this list of conditions and the following disclaimer in the
  34   documentation and/or other materials provided with the distribution.
  35
  36   Neither the name of the University of Colorado nor the names of its
  37   contributors may be used to endorse or promote products derived from
  38   this software without specific prior written permission.
  39
  40   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  41   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  42   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  43   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  44   COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  45   INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  46   BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  48   CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49   LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  50   ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  51   POSSIBILITY OF SUCH DAMAGE.]
  52
  53 ******************************************************************************/
  54
  55 #include "util.h"
  56 #include "cuddInt.h"
  57
  58
  59 /*---------------------------------------------------------------------------*/
  60 /* Constant declarations                                                     */
  61 /*---------------------------------------------------------------------------*/
  62
  63
  64 /*---------------------------------------------------------------------------*/
  65 /* Stucture declarations                                                     */
  66 /*---------------------------------------------------------------------------*/
  67
  68
  69 /*---------------------------------------------------------------------------*/
  70 /* Type declarations                                                         */
  71 /*---------------------------------------------------------------------------*/
  72
  73
  74 /*---------------------------------------------------------------------------*/
  75 /* Variable declarations                                                     */
  76 /*---------------------------------------------------------------------------*/
  77
  78 #ifndef lint
  79 static char rcsid[] DD_UNUSED = "$Id: cuddSign.c,v 1.22 2009/02/20 02:14:58 fabio Exp $";
  80 #endif
  81
  82 static int    size;
  83
  84 #ifdef DD_STATS
  85 static int num_calls;   /* should equal 2n-1 (n is the # of nodes) */
  86 static int table_mem;
  87 #endif
  88
  89
  90 /*---------------------------------------------------------------------------*/
  91 /* Macro declarations                                                        */
  92 /*---------------------------------------------------------------------------*/
  93
  94
  95 /**AutomaticStart*************************************************************/
  96
  97 /*---------------------------------------------------------------------------*/
  98 /* Static function prototypes                                                */
  99 /*---------------------------------------------------------------------------*/
 100
 101 static double * ddCofMintermAux (DdManager *dd, DdNode *node, st_table *table);
 102
 103 /**AutomaticEnd***************************************************************/
 104
 105
 106 /*---------------------------------------------------------------------------*/
 107 /* Definition of exported functions                                          */
 108 /*---------------------------------------------------------------------------*/
 109
 110 /**Function********************************************************************
 111
 112   Synopsis [Computes the fraction of minterms in the on-set of all the
 113   positive cofactors of a BDD or ADD.]
 114
 115   Description [Computes the fraction of minterms in the on-set of all
 116   the positive cofactors of DD. Returns the pointer to an array of
 117   doubles if successful; NULL otherwise. The array has as many
 118   positions as there are BDD variables in the manager plus one. The
 119   last position of the array contains the fraction of the minterms in
 120   the ON-set of the function represented by the BDD or ADD. The other
 121   positions of the array hold the variable signatures.]
 122
 123   SideEffects [None]
 124
 125 ******************************************************************************/
 126 double *
 127 Cudd_CofMinterm(
 128   DdManager * dd,
 129   DdNode * node)
 130 {
 131     st_table    *table;
 132     double      *values;
 133     double      *result = NULL;
 134     int         i, firstLevel;
 135
 136 #ifdef DD_STATS
 137     long startTime;
 138     startTime = util_cpu_time();
 139     num_calls = 0;
 140     table_mem = sizeof(st_table);
 141 #endif
 142
 143     table = st_init_table(st_ptrcmp, st_ptrhash);
 144     if (table == NULL) {
 145         (void) fprintf(dd->err,
 146                        "out-of-memory, couldn't measure DD cofactors.\n");
 147         dd->errorCode = CUDD_MEMORY_OUT;
 148         return(NULL);
 149     }
 150     size = dd->size;
 151     values = ddCofMintermAux(dd, node, table);
 152     if (values != NULL) {
 153         result = ALLOC(double,size + 1);
 154         if (result != NULL) {
 155 #ifdef DD_STATS
 156             table_mem += (size + 1) * sizeof(double);
 157 #endif
 158             if (Cudd_IsConstant(node))
 159                 firstLevel = 1;
 160             else
 161                 firstLevel = cuddI(dd,Cudd_Regular(node)->index);
 162             for (i = 0; i < size; i++) {
 163                 if (i >= cuddI(dd,Cudd_Regular(node)->index)) {
 164                     result[dd->invperm[i]] = values[i - firstLevel];
 165                 } else {
 166                     result[dd->invperm[i]] = values[size - firstLevel];
 167                 }
 168             }
 169             result[size] = values[size - firstLevel];
 170         } else {
 171             dd->errorCode = CUDD_MEMORY_OUT;
 172         }
 173     }
 174
 175 #ifdef DD_STATS
 176     table_mem += table->num_bins * sizeof(st_table_entry *);
 177 #endif
 178     if (Cudd_Regular(node)->ref == 1) FREE(values);
 179     st_foreach(table, cuddStCountfree, NULL);
 180     st_free_table(table);
 181 #ifdef DD_STATS
 182     (void) fprintf(dd->out,"Number of calls: %d\tTable memory: %d bytes\n",
 183                   num_calls, table_mem);
 184     (void) fprintf(dd->out,"Time to compute measures: %s\n",
 185                   util_print_time(util_cpu_time() - startTime));
 186 #endif
 187     if (result == NULL) {
 188         (void) fprintf(dd->out,
 189                        "out-of-memory, couldn't measure DD cofactors.\n");
 190         dd->errorCode = CUDD_MEMORY_OUT;
 191     }
 192     return(result);
 193
 194 } /* end of Cudd_CofMinterm */
 195
 196
 197 /*---------------------------------------------------------------------------*/
 198 /* Definition of internal functions                                          */
 199 /*---------------------------------------------------------------------------*/
 200
 201
 202 /*---------------------------------------------------------------------------*/
 203 /* Definition of static functions                                            */
 204 /*---------------------------------------------------------------------------*/
 205
 206
 207 /**Function********************************************************************
 208
 209   Synopsis    [Recursive Step for Cudd_CofMinterm function.]
 210
 211   Description [Traverses the DD node and computes the fraction of
 212   minterms in the on-set of all positive cofactors simultaneously.
 213   It allocates an array with two more entries than there are
 214   variables below the one labeling the node.  One extra entry (the
 215   first in the array) is for the variable labeling the node. The other
 216   entry (the last one in the array) holds the fraction of minterms of
 217   the function rooted at node.  Each other entry holds the value for
 218   one cofactor. The array is put in a symbol table, to avoid repeated
 219   computation, and its address is returned by the procedure, for use
 220   by the caller.  Returns a pointer to the array of cofactor measures.]
 221
 222   SideEffects [None]
 223
 224   SeeAlso     []
 225
 226 ******************************************************************************/
 227 static double *
 228 ddCofMintermAux(
 229   DdManager * dd,
 230   DdNode * node,
 231   st_table * table)
 232 {
 233     DdNode      *N;             /* regular version of node */
 234     DdNode      *Nv, *Nnv;
 235     double      *values;
 236     double      *valuesT, *valuesE;
 237     int         i;
 238     int         localSize, localSizeT, localSizeE;
 239     double      vT, vE;
 240
 241     statLine(dd);
 242 #ifdef DD_STATS
 243     num_calls++;
 244 #endif
 245
 246     if (st_lookup(table, node, &values)) {
 247         return(values);
 248     }
 249
 250     N = Cudd_Regular(node);
 251     if (cuddIsConstant(N)) {
 252         localSize = 1;
 253     } else {
 254         localSize = size - cuddI(dd,N->index) + 1;
 255     }
 256     values = ALLOC(double, localSize);
 257     if (values == NULL) {
 258         dd->errorCode = CUDD_MEMORY_OUT;
 259         return(NULL);
 260     }
 261
 262     if (cuddIsConstant(N)) {
 263         if (node == DD_ZERO(dd) || node == Cudd_Not(DD_ONE(dd))) {
 264             values[0] = 0.0;
 265         } else {
 266             values[0] = 1.0;
 267         }
 268     } else {
 269         Nv = Cudd_NotCond(cuddT(N),N!=node);
 270         Nnv = Cudd_NotCond(cuddE(N),N!=node);
 271
 272         valuesT = ddCofMintermAux(dd, Nv, table);
 273         if (valuesT == NULL) return(NULL);
 274         valuesE = ddCofMintermAux(dd, Nnv, table);
 275         if (valuesE == NULL) return(NULL);
 276
 277         if (Cudd_IsConstant(Nv)) {
 278             localSizeT = 1;
 279         } else {
 280             localSizeT = size - cuddI(dd,Cudd_Regular(Nv)->index) + 1;
 281         }
 282         if (Cudd_IsConstant(Nnv)) {
 283             localSizeE = 1;
 284         } else {
 285             localSizeE = size - cuddI(dd,Cudd_Regular(Nnv)->index) + 1;
 286         }
 287         values[0] = valuesT[localSizeT - 1];
 288         for (i = 1; i < localSize; i++) {
 289             if (i >= cuddI(dd,Cudd_Regular(Nv)->index) - cuddI(dd,N->index)) {
 290                 vT = valuesT[i - cuddI(dd,Cudd_Regular(Nv)->index) +
 291                             cuddI(dd,N->index)];
 292             } else {
 293                 vT = valuesT[localSizeT - 1];
 294             }
 295             if (i >= cuddI(dd,Cudd_Regular(Nnv)->index) - cuddI(dd,N->index)) {
 296                 vE = valuesE[i - cuddI(dd,Cudd_Regular(Nnv)->index) +
 297                             cuddI(dd,N->index)];
 298             } else {
 299                 vE = valuesE[localSizeE - 1];
 300             }
 301             values[i] = (vT + vE) / 2.0;
 302         }
 303         if (Cudd_Regular(Nv)->ref == 1) FREE(valuesT);
 304         if (Cudd_Regular(Nnv)->ref == 1) FREE(valuesE);
 305     }
 306
 307     if (N->ref > 1) {
 308         if (st_add_direct(table, (char *) node, (char *) values) == ST_OUT_OF_MEM) {
 309             FREE(values);
 310             return(NULL);
 311         }
 312 #ifdef DD_STATS
 313         table_mem += localSize * sizeof(double) + sizeof(st_table_entry);
 314 #endif
 315     }
 316     return(values);
 317
 318 } /* end of ddCofMintermAux */