1 //******************************************************************************
2 //
3 // File: DoubleOp.java
4 // Package: edu.rit.pj.reduction
5 // Unit: Class edu.rit.pj.reduction.DoubleOp
6 //
7 // This Java source file is copyright (C) 2007 by Alan Kaminsky. All rights
8 // reserved. For further information, contact the author, Alan Kaminsky, at
9 // ark@cs.rit.edu.
10 //
11 // This Java source file is part of the Parallel Java Library ("PJ"). PJ is free
12 // software; you can redistribute it and/or modify it under the terms of the GNU
13 // General Public License as published by the Free Software Foundation; either
14 // version 3 of the License, or (at your option) any later version.
15 //
16 // PJ is distributed in the hope that it will be useful, but WITHOUT ANY
17 // WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
18 // A PARTICULAR PURPOSE. See the GNU General Public License for more details.
19 //
20 // Linking this library statically or dynamically with other modules is making a
21 // combined work based on this library. Thus, the terms and conditions of the GNU
22 // General Public License cover the whole combination.
23 //
24 // As a special exception, the copyright holders of this library give you
25 // permission to link this library with independent modules to produce an
26 // executable, regardless of the license terms of these independent modules, and
27 // to copy and distribute the resulting executable under terms of your choice,
28 // provided that you also meet, for each linked independent module, the terms
29 // and conditions of the license of that module. An independent module is a module
30 // which is not derived from or based on this library. If you modify this library,
31 // you may extend this exception to your version of the library, but you are not
32 // obligated to do so. If you do not wish to do so, delete this exception
33 // statement from your version.
34 //
35 // A copy of the GNU General Public License is provided in the file gpl.txt. You
36 // may also obtain a copy of the GNU General Public License on the World Wide
37 // Web at http://www.gnu.org/licenses/gpl.html.
38 //
39 //******************************************************************************
40 package edu.rit.pj.reduction;
41
42 /**
43 * Class DoubleOp is the abstract base class for a binary operation on double
44 * values, used to do reduction in a parallel program.
45 *
46 * @author Alan Kaminsky
47 * @version 05-Jun-2007
48 */
49 public abstract class DoubleOp
50 extends Op {
51
52 // Hidden constructors.
53 /**
54 * Construct a new double binary operation.
55 */
56 protected DoubleOp() {
57 super();
58 }
59
60 // Exported operations.
61 /**
62 * Perform this binary operation.
63 *
64 * @param x First argument.
65 * @param y Second argument.
66 * @return (<code>x</code> <I>op</I> <code>y</code>), where <I>op</I> stands for
67 * this binary operation.
68 */
69 public abstract double op(double x,
70 double y);
71
72 // Exported constants.
73 /**
74 * The double sum binary operation.
75 */
76 public static final DoubleOp SUM
77 = new DoubleOp() {
78 public double op(double x,
79 double y) {
80 return x + y;
81 }
82 };
83
84 /**
85 * The double product binary operation.
86 */
87 public static final DoubleOp PRODUCT
88 = new DoubleOp() {
89 public double op(double x,
90 double y) {
91 return x * y;
92 }
93 };
94
95 /**
96 * The double minimum binary operation.
97 */
98 public static final DoubleOp MINIMUM
99 = new DoubleOp() {
100 public double op(double x,
101 double y) {
102 return Math.min(x, y);
103 }
104 };
105
106 /**
107 * The double maximum binary operation.
108 */
109 public static final DoubleOp MAXIMUM
110 = new DoubleOp() {
111 public double op(double x,
112 double y) {
113 return Math.max(x, y);
114 }
115 };
116
117 }