1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.nabla.forward.arithmetic;
18
19 import org.apache.commons.nabla.DifferentiationException;
20 import org.apache.commons.nabla.forward.analysis.InstructionsTransformer;
21 import org.apache.commons.nabla.forward.analysis.MethodDifferentiator;
22 import org.objectweb.asm.Opcodes;
23 import org.objectweb.asm.Type;
24 import org.objectweb.asm.tree.AbstractInsnNode;
25 import org.objectweb.asm.tree.InsnList;
26 import org.objectweb.asm.tree.InsnNode;
27 import org.objectweb.asm.tree.MethodInsnNode;
28 import org.objectweb.asm.tree.VarInsnNode;
29
30 /** Differentiation transformer for DREM instructions.
31 * @version $Id$
32 */
33 public class DRemTransformer implements InstructionsTransformer {
34
35 /** Name of the {@link org.apache.commons.math3.analysis.differentiation.DerivativeStructure} method corresponding to the remainder. */
36 private static final String REMAINDER_METHOD = "remainder";
37
38 /** Name of the {@link org.apache.commons.math3.analysis.differentiation.DerivativeStructure} method corresponding to the value getter. */
39 private static final String VALUE_GETTER_METHOD = "getValue";
40
41 /** Name of the {@link org.apache.commons.math3.analysis.differentiation.DerivativeStructure} method corresponding to the multiplication. */
42 private static final String MULTIPLY_METHOD = "multiply";
43
44 /** Name of the {@link org.apache.commons.math3.analysis.differentiation.DerivativeStructure} method corresponding to the addition. */
45 private static final String ADD_METHOD = "add";
46
47 /** Indicator for top stack element conversion. */
48 private final boolean stack0Converted;
49
50 /** Indicator for next to top stack element conversion. */
51 private final boolean stack1Converted;
52
53 /** Simple constructor.
54 * @param stack0Converted if true, the top level stack element has already been converted
55 * @param stack1Converted if true, the next to top level stack element has already been converted
56 */
57 public DRemTransformer(final boolean stack0Converted, final boolean stack1Converted) {
58 this.stack0Converted = stack0Converted;
59 this.stack1Converted = stack1Converted;
60 }
61
62 /** {@inheritDoc} */
63 public InsnList getReplacement(final AbstractInsnNode insn,
64 final MethodDifferentiator methodDifferentiator)
65 throws DifferentiationException {
66
67 final InsnList list = new InsnList();
68
69 if (stack1Converted) {
70 if (stack0Converted) {
71 list.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, DS_TYPE.getInternalName(),
72 REMAINDER_METHOD,
73 Type.getMethodDescriptor(DS_TYPE, DS_TYPE)));
74 } else {
75 list.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, DS_TYPE.getInternalName(),
76 REMAINDER_METHOD,
77 Type.getMethodDescriptor(DS_TYPE, Type.DOUBLE_TYPE)));
78 }
79 } else {
80
81 // set up a temporary variable
82 final int tmp1 = methodDifferentiator.getTmp(1);
83
84 // operand stack initial state: a, ds_b
85 list.add(new InsnNode(Opcodes.DUP_X2)); // => ds_b, a, ds_b
86 list.add(new InsnNode(Opcodes.POP)); // => ds_b, a
87 list.add(new VarInsnNode(Opcodes.DSTORE, tmp1)); // => ds_b
88 list.add(new InsnNode(Opcodes.DUP)); // => ds_b, ds_b
89 list.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, DS_TYPE.getInternalName(),
90 VALUE_GETTER_METHOD,
91 Type.getMethodDescriptor(Type.DOUBLE_TYPE))); // => ds_b, b0
92 list.add(new InsnNode(Opcodes.DUP2)); // => ds_b, b0, b0
93 list.add(new VarInsnNode(Opcodes.DLOAD, tmp1)); // => ds_b, b0, b0, a
94 list.add(new InsnNode(Opcodes.DUP2_X2)); // => ds_b, b0, a, b0, a
95 list.add(new InsnNode(Opcodes.POP2)); // => ds_b, b0, a, b0
96 list.add(new InsnNode(Opcodes.DREM)); // => ds_b, b0, a%b0
97 list.add(new VarInsnNode(Opcodes.DLOAD, tmp1)); // => ds_b, b0, a%b0, a
98 list.add(new InsnNode(Opcodes.DSUB)); // => ds_b, b0, a%b0-a
99 list.add(new InsnNode(Opcodes.DUP2_X2)); // => ds_b, a%b0-a, b0, a%b0-a
100 list.add(new InsnNode(Opcodes.POP2)); // => ds_b, a%b0-a, b0
101 list.add(new InsnNode(Opcodes.DDIV)); // => ds_b, q=(a%b0-a)/b0
102 list.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, DS_TYPE.getInternalName(),
103 MULTIPLY_METHOD,
104 Type.getMethodDescriptor(DS_TYPE, Type.DOUBLE_TYPE))); // => q*b
105 list.add(new VarInsnNode(Opcodes.DLOAD, tmp1)); // => q*b, a
106 list.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, DS_TYPE.getInternalName(),
107 ADD_METHOD,
108 Type.getMethodDescriptor(DS_TYPE, Type.DOUBLE_TYPE))); // => a+q*b
109
110 }
111
112 return list;
113
114 }
115
116 }