source: vis_dev/glu-2.3/src/cuBdd/cuddAddInv.c@ 42

Last change on this file since 42 was 13, checked in by cecile, 15 years ago

library glu 2.3
File size: 6.7 KB
RevLine 
[13]1/**CFile***********************************************************************
2
3 FileName [cuddAddInv.c]
4
5 PackageName [cudd]
6
7 Synopsis [Function to compute the scalar inverse of an ADD.]
8
9 Description [External procedures included in this module:
10 <ul>
11 <li> Cudd_addScalarInverse()
12 </ul>
13 Internal procedures included in this module:
14 <ul>
15 <li> cuddAddScalarInverseRecur()
16 </ul>]
17
18 Author [Fabio Somenzi]
19
20 Copyright [Copyright (c) 1995-2004, Regents of the University of Colorado
21
22 All rights reserved.
23
24 Redistribution and use in source and binary forms, with or without
25 modification, are permitted provided that the following conditions
26 are met:
27
28 Redistributions of source code must retain the above copyright
29 notice, this list of conditions and the following disclaimer.
30
31 Redistributions in binary form must reproduce the above copyright
32 notice, this list of conditions and the following disclaimer in the
33 documentation and/or other materials provided with the distribution.
34
35 Neither the name of the University of Colorado nor the names of its
36 contributors may be used to endorse or promote products derived from
37 this software without specific prior written permission.
38
39 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
40 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
41 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
42 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
43 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
44 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
45 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
47 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
49 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
50 POSSIBILITY OF SUCH DAMAGE.]
51
52******************************************************************************/
53
54#include "util.h"
55#include "cuddInt.h"
56
57
58/*---------------------------------------------------------------------------*/
59/* Constant declarations */
60/*---------------------------------------------------------------------------*/
61
62
63/*---------------------------------------------------------------------------*/
64/* Stucture declarations */
65/*---------------------------------------------------------------------------*/
66
67
68/*---------------------------------------------------------------------------*/
69/* Type declarations */
70/*---------------------------------------------------------------------------*/
71
72
73/*---------------------------------------------------------------------------*/
74/* Variable declarations */
75/*---------------------------------------------------------------------------*/
76
77#ifndef lint
78static char rcsid[] DD_UNUSED = "$Id: cuddAddInv.c,v 1.9 2004/08/13 18:04:45 fabio Exp $";
79#endif
80
81
82/*---------------------------------------------------------------------------*/
83/* Macro declarations */
84/*---------------------------------------------------------------------------*/
85
86
87/**AutomaticStart*************************************************************/
88
89/*---------------------------------------------------------------------------*/
90/* Static function prototypes */
91/*---------------------------------------------------------------------------*/
92
93
94/**AutomaticEnd***************************************************************/
95
96
97/*---------------------------------------------------------------------------*/
98/* Definition of exported functions */
99/*---------------------------------------------------------------------------*/
100
101
102/**Function********************************************************************
103
104 Synopsis [Computes the scalar inverse of an ADD.]
105
106 Description [Computes an n ADD where the discriminants are the
107 multiplicative inverses of the corresponding discriminants of the
108 argument ADD. Returns a pointer to the resulting ADD in case of
109 success. Returns NULL if any discriminants smaller than epsilon is
110 encountered.]
111
112 SideEffects [None]
113
114******************************************************************************/
115DdNode *
116Cudd_addScalarInverse(
117 DdManager * dd,
118 DdNode * f,
119 DdNode * epsilon)
120{
121 DdNode *res;
122
123 if (!cuddIsConstant(epsilon)) {
124 (void) fprintf(dd->err,"Invalid epsilon\n");
125 return(NULL);
126 }
127 do {
128 dd->reordered = 0;
129 res = cuddAddScalarInverseRecur(dd,f,epsilon);
130 } while (dd->reordered == 1);
131 return(res);
132
133} /* end of Cudd_addScalarInverse */
134
135/*---------------------------------------------------------------------------*/
136/* Definition of internal functions */
137/*---------------------------------------------------------------------------*/
138
139
140/**Function********************************************************************
141
142 Synopsis [Performs the recursive step of addScalarInverse.]
143
144 Description [Returns a pointer to the resulting ADD in case of
145 success. Returns NULL if any discriminants smaller than epsilon is
146 encountered.]
147
148 SideEffects [None]
149
150******************************************************************************/
151DdNode *
152cuddAddScalarInverseRecur(
153 DdManager * dd,
154 DdNode * f,
155 DdNode * epsilon)
156{
157 DdNode *t, *e, *res;
158 CUDD_VALUE_TYPE value;
159
160 statLine(dd);
161 if (cuddIsConstant(f)) {
162 if (ddAbs(cuddV(f)) < cuddV(epsilon)) return(NULL);
163 value = 1.0 / cuddV(f);
164 res = cuddUniqueConst(dd,value);
165 return(res);
166 }
167
168 res = cuddCacheLookup2(dd,Cudd_addScalarInverse,f,epsilon);
169 if (res != NULL) return(res);
170
171 t = cuddAddScalarInverseRecur(dd,cuddT(f),epsilon);
172 if (t == NULL) return(NULL);
173 cuddRef(t);
174
175 e = cuddAddScalarInverseRecur(dd,cuddE(f),epsilon);
176 if (e == NULL) {
177 Cudd_RecursiveDeref(dd, t);
178 return(NULL);
179 }
180 cuddRef(e);
181
182 res = (t == e) ? t : cuddUniqueInter(dd,(int)f->index,t,e);
183 if (res == NULL) {
184 Cudd_RecursiveDeref(dd, t);
185 Cudd_RecursiveDeref(dd, e);
186 return(NULL);
187 }
188 cuddDeref(t);
189 cuddDeref(e);
190
191 cuddCacheInsert2(dd,Cudd_addScalarInverse,f,epsilon,res);
192
193 return(res);
194
195} /* end of cuddAddScalarInverseRecur */
196
197
198/*---------------------------------------------------------------------------*/
199/* Definition of static functions */
200/*---------------------------------------------------------------------------*/
201
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