Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
DDivTransformer2 |
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| 1.0;1 | ||||
DDivTransformer2$1 |
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| 1.0;1 | ||||
DDivTransformer2$LazyHolder |
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| 1.0;1 |
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.automatic.arithmetic; | |
18 | ||
19 | import org.apache.commons.nabla.automatic.analysis.InstructionsTransformer; | |
20 | import org.apache.commons.nabla.automatic.analysis.MethodDifferentiator; | |
21 | import org.apache.commons.nabla.core.DifferentiationException; | |
22 | import org.objectweb.asm.Opcodes; | |
23 | import org.objectweb.asm.tree.AbstractInsnNode; | |
24 | import org.objectweb.asm.tree.InsnList; | |
25 | import org.objectweb.asm.tree.InsnNode; | |
26 | import org.objectweb.asm.tree.VarInsnNode; | |
27 | ||
28 | /** Differentiation transformer for DDIV instructions. | |
29 | * <p>This transformer is used when only the second argument | |
30 | * of DDIV is an expanded differential pair. It implements the | |
31 | * classical differentiation rules for division.</p> | |
32 | * @see DDivTransformer1 | |
33 | * @see DDivTransformer12 | |
34 | */ | |
35 | 1 | public class DDivTransformer2 implements InstructionsTransformer { |
36 | ||
37 | /** Holder for the singleton instance.*/ | |
38 | 2 | private static class LazyHolder { |
39 | /** The singleton instance. */ | |
40 | 1 | private static final InstructionsTransformer INSTANCE = new DDivTransformer2(); |
41 | } | |
42 | ||
43 | /** Hidden constructor. | |
44 | */ | |
45 | 1 | private DDivTransformer2() { |
46 | 1 | } |
47 | ||
48 | /** Get the singleton instance. | |
49 | * <p>We use here the Initialization on Demand Holder idiom.</p> | |
50 | * @return the singleton instance | |
51 | */ | |
52 | public static InstructionsTransformer getInstance() { | |
53 | 2 | return LazyHolder.INSTANCE; |
54 | } | |
55 | ||
56 | /** {@inheritDoc} */ | |
57 | public InsnList getReplacement(final AbstractInsnNode insn, | |
58 | final MethodDifferentiator methodDifferentiator) | |
59 | throws DifferentiationException { | |
60 | ||
61 | 2 | final int tmp1 = methodDifferentiator.getTmp(1); |
62 | 2 | final int tmp2 = methodDifferentiator.getTmp(2); |
63 | 2 | final InsnList list = new InsnList(); |
64 | ||
65 | // operand stack initial state: a, b0, b1 | |
66 | 2 | list.add(new VarInsnNode(Opcodes.DSTORE, tmp1)); // => a, b0 |
67 | 2 | list.add(new InsnNode(Opcodes.DUP2)); // => a, b0, b0 |
68 | 2 | list.add(new VarInsnNode(Opcodes.DSTORE, tmp2)); // => a, b0 |
69 | 2 | list.add(new InsnNode(Opcodes.DDIV)); // => a/b0 |
70 | 2 | list.add(new InsnNode(Opcodes.DUP2)); // => a/b0, a/b0 |
71 | 2 | list.add(new VarInsnNode(Opcodes.DLOAD, tmp1)); // => a/b0, a/b0, b1 |
72 | 2 | list.add(new InsnNode(Opcodes.DMUL)); // => a/b0, a*b1/b0 |
73 | 2 | list.add(new VarInsnNode(Opcodes.DLOAD, tmp2)); // => a/b0, a*b1/b0, b0 |
74 | 2 | list.add(new InsnNode(Opcodes.DDIV)); // => a/b0, a*b1/b0^2 |
75 | 2 | list.add(new InsnNode(Opcodes.DNEG)); // => a/b0, -a*b1/b0^2 |
76 | ||
77 | 2 | return list; |
78 | ||
79 | } | |
80 | ||
81 | } |