Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
DSubTransformer12 |
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| 1.0;1 | ||||
DSubTransformer12$1 |
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| 1.0;1 | ||||
DSubTransformer12$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 DSUB instructions. | |
29 | * <p>This transformer is used when both arguments of DSUB are | |
30 | * expanded differential pairs. It implements the classical | |
31 | * differentiation rules for subtraction.</p> | |
32 | * @see DSubTransformer1 | |
33 | * @see DSubTransformer2 | |
34 | */ | |
35 | 1 | public class DSubTransformer12 implements InstructionsTransformer { |
36 | ||
37 | /** Holder for the singleton instance.*/ | |
38 | 1 | private static class LazyHolder { |
39 | /** The singleton instance. */ | |
40 | 1 | private static final InstructionsTransformer INSTANCE = new DSubTransformer12(); |
41 | } | |
42 | ||
43 | /** Hidden constructor. | |
44 | */ | |
45 | 1 | private DSubTransformer12() { |
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 | 1 | return LazyHolder.INSTANCE; |
54 | } | |
55 | ||
56 | /** {@inheritDoc} */ | |
57 | public InsnList getReplacement(final AbstractInsnNode insn, | |
58 | final MethodDifferentiator methodDifferentiator) | |
59 | throws DifferentiationException { | |
60 | ||
61 | 1 | final int tmp = methodDifferentiator.getTmp(1); |
62 | 1 | final InsnList list = new InsnList(); |
63 | ||
64 | // operand stack initial state: a0, a1, b0, b1 | |
65 | 1 | list.add(new VarInsnNode(Opcodes.DSTORE, tmp)); // => a0, a1, b0 |
66 | 1 | list.add(new InsnNode(Opcodes.DUP2_X2)); // => a0, b0, a1, b0 |
67 | 1 | list.add(new InsnNode(Opcodes.POP2)); // => a0, b0, a1 |
68 | 1 | list.add(new VarInsnNode(Opcodes.DLOAD, tmp)); // => a0, b0, a1, b1 |
69 | 1 | list.add(new InsnNode(Opcodes.DSUB)); // => a0, b0, a1-b1 |
70 | 1 | list.add(new VarInsnNode(Opcodes.DSTORE, tmp)); // => a0, b0 |
71 | 1 | list.add(new InsnNode(Opcodes.DSUB)); // => a0-b0 |
72 | 1 | list.add(new VarInsnNode(Opcodes.DLOAD, tmp)); // => a0-b0, a1-b1 |
73 | ||
74 | 1 | return list; |
75 | ||
76 | } | |
77 | ||
78 | } |