this repo has no description
dekker.one
1/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
2/*
3 * Main authors:
4 * Christian Schulte <schulte@gecode.org>
5 * Guido Tack <tack@gecode.org>
6 * Vincent Barichard <Vincent.Barichard@univ-angers.fr>
7 *
8 * Copyright:
9 * Christian Schulte, 2004
10 * Guido Tack, 2006
11 * Vincent Barichard, 2012
12 *
13 * This file is part of Gecode, the generic constraint
14 * development environment:
15 * http://www.gecode.org
16 *
17 * Permission is hereby granted, free of charge, to any person obtaining
18 * a copy of this software and associated documentation files (the
19 * "Software"), to deal in the Software without restriction, including
20 * without limitation the rights to use, copy, modify, merge, publish,
21 * distribute, sublicense, and/or sell copies of the Software, and to
22 * permit persons to whom the Software is furnished to do so, subject to
23 * the following conditions:
24 *
25 * The above copyright notice and this permission notice shall be
26 * included in all copies or substantial portions of the Software.
27 *
28 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
29 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
30 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
31 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
32 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
33 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
34 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
35 *
36 */
37
38namespace Gecode { namespace Float { namespace Arithmetic {
39
40 /*
41 * Positive bounds consistent squaring
42 *
43 */
44 template<class VA, class VB>
45 forceinline
46 SqrPlus<VA,VB>::SqrPlus(Home home, VA x0, VB x1)
47 : MixBinaryPropagator<VA,PC_FLOAT_BND,VB,PC_FLOAT_BND>(home,x0,x1) {}
48
49 template<class VA, class VB>
50 forceinline ExecStatus
51 SqrPlus<VA,VB>::post(Home home, VA x0, VB x1) {
52 if (x0 == x1) {
53 if (x0.assigned())
54 return ((x0.val() == 0) || (x0.val() == 1))? ES_OK : ES_FAILED;
55 } else {
56 GECODE_ME_CHECK(x0.eq(home,sqrt(x1.val())));
57 GECODE_ME_CHECK(x1.eq(home,sqr(x0.val())));
58 }
59
60 (void) new (home) SqrPlus<VA,VB>(home,x0,x1);
61 return ES_OK;
62 }
63
64 template<class VA, class VB>
65 forceinline
66 SqrPlus<VA,VB>::SqrPlus(Space& home, SqrPlus<VA,VB>& p)
67 : MixBinaryPropagator<VA,PC_FLOAT_BND,VB,PC_FLOAT_BND>(home,p) {}
68
69 template<class VA, class VB>
70 Actor*
71 SqrPlus<VA,VB>::copy(Space& home) {
72 return new (home) SqrPlus<VA,VB>(home,*this);
73 }
74
75 template<class VA, class VB>
76 ExecStatus
77 SqrPlus<VA,VB>::propagate(Space& home, const ModEventDelta&) {
78 if (x0 == x1) {
79 if (x0.max() < 1) GECODE_ME_CHECK(x0.eq(home,0));
80 else if (x0.min() > 0) GECODE_ME_CHECK(x0.eq(home,1));
81 if (x0.assigned())
82 return ((x0.val() == 0) || (x0.val() == 1))? home.ES_SUBSUMED(*this) : ES_FAILED;
83 } else {
84 GECODE_ME_CHECK(x0.eq(home,sqrt(x1.val())));
85 GECODE_ME_CHECK(x1.eq(home,sqr(x0.val())));
86 if (x0.assigned() || x1.assigned()) return home.ES_SUBSUMED(*this);
87 }
88
89 return ES_FIX;
90 }
91
92
93 /*
94 * Bounds consistent squaring
95 *
96 */
97
98 template<class View>
99 forceinline
100 Sqr<View>::Sqr(Home home, View x0, View x1)
101 : BinaryPropagator<View,PC_FLOAT_BND>(home,x0,x1) {}
102
103 template<class View>
104 forceinline ExecStatus
105 Sqr<View>::post(Home home, View x0, View x1) {
106 GECODE_ME_CHECK(x1.gq(home,0));
107 if (x0 == x1) {
108 if (x0.assigned())
109 return ((x0.val() == 0) || (x0.val() == 1))? ES_OK : ES_FAILED;
110 GECODE_ME_CHECK(x1.lq(home,1));
111 return SqrPlus<FloatView,FloatView>::post(home,x0,x1);
112 } else {
113 if (x0.min() >= 0)
114 return SqrPlus<FloatView,FloatView>::post(home,x0,x1);
115 if (x0.max() <= 0)
116 return SqrPlus<MinusView,FloatView>::post(home,MinusView(x0),x1);
117 GECODE_ME_CHECK(x1.eq(home,sqr(x0.val())));
118 (void) new (home) Sqr<View>(home,x0,x1);
119 }
120 return ES_OK;
121 }
122
123 template<class View>
124 forceinline
125 Sqr<View>::Sqr(Space& home, Sqr<View>& p)
126 : BinaryPropagator<View,PC_FLOAT_BND>(home,p) {}
127
128 template<class View>
129 Actor*
130 Sqr<View>::copy(Space& home) {
131 return new (home) Sqr<View>(home,*this);
132 }
133
134 template<class View>
135 ExecStatus
136 Sqr<View>::propagate(Space& home, const ModEventDelta&) {
137 assert(x1.min() >= 0);
138 if (x0.min() >= 0)
139 GECODE_REWRITE(*this,(SqrPlus<FloatView,FloatView>::post(home(*this),x0,x1)));
140 if (x0.max() <= 0)
141 GECODE_REWRITE(*this,(SqrPlus<MinusView,FloatView>::post(home(*this),
142 MinusView(x0),x1)));
143
144 GECODE_ME_CHECK(x1.eq(home,sqr(x0.val())));
145 Rounding r;
146 FloatVal z = sqrt(x1.val());
147 if (x0.min() > -r.sqrt_up(x1.min()))
148 GECODE_ME_CHECK(x0.eq(home,z));
149 else if (x0.max() < r.sqrt_down(x1.min()))
150 GECODE_ME_CHECK(x0.eq(home,-z));
151 else
152 GECODE_ME_CHECK(x0.eq(home,hull(z,-z)));
153
154 return ES_NOFIX;
155 }
156
157
158 /*
159 * Bounds consistent square root operator
160 *
161 */
162
163 template<class A, class B>
164 forceinline
165 Sqrt<A,B>::Sqrt(Home home, A x0, B x1)
166 : MixBinaryPropagator<A,PC_FLOAT_BND,B,PC_FLOAT_BND>(home,x0,x1) {}
167
168 template<class A, class B>
169 ExecStatus
170 Sqrt<A,B>::post(Home home, A x0, B x1) {
171 GECODE_ME_CHECK(x0.gq(home,0));
172 if (x0 == x1) {
173 if (x0.assigned())
174 return ((x0.val() == 0) || (x0.val() == 1))? ES_OK : ES_FAILED;
175 GECODE_ME_CHECK(x0.lq(home,1));
176 (void) new (home) Sqrt<A,B>(home,x0,x1);
177 } else {
178 GECODE_ME_CHECK(x1.eq(home,sqrt(x0.val())));
179 (void) new (home) Sqrt<A,B>(home,x0,x1);
180 }
181 return ES_OK;
182 }
183
184 template<class A, class B>
185 forceinline
186 Sqrt<A,B>::Sqrt(Space& home, Sqrt<A,B>& p)
187 : MixBinaryPropagator<A,PC_FLOAT_BND,B,PC_FLOAT_BND>(home,p) {}
188
189 template<class A, class B>
190 Actor*
191 Sqrt<A,B>::copy(Space& home) {
192 return new (home) Sqrt<A,B>(home,*this);
193 }
194
195 template<class A, class B>
196 ExecStatus
197 Sqrt<A,B>::propagate(Space& home, const ModEventDelta&) {
198 if (x0 == x1) {
199 if (x0.max() < 1) GECODE_ME_CHECK(x0.eq(home,0));
200 else if (x0.min() > 0) GECODE_ME_CHECK(x0.eq(home,1));
201 if (x0.assigned())
202 return ((x0.val() == 0) || (x0.val() == 1))? home.ES_SUBSUMED(*this) : ES_FAILED;
203 } else {
204 GECODE_ME_CHECK(x0.eq(home,sqr(x1.val())));
205 GECODE_ME_CHECK(x1.eq(home,sqrt(x0.val())));
206 if (x0.assigned() || x1.assigned()) return home.ES_SUBSUMED(*this);
207 }
208
209 return ES_FIX;
210 }
211
212}}}
213
214// STATISTICS: float-prop
215