Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
DRemTransformer2 |
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| 1.0;1 | ||||
DRemTransformer2$1 |
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| 1.0;1 | ||||
DRemTransformer2$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 DREM instructions. | |
29 | * <p>This transformer is used when only the second argument | |
30 | * of DREM is an expanded differential pair. It is based on | |
31 | * the identity: <code>a%b = a - q * b</code> where q is an | |
32 | * integer.</p> | |
33 | * @see DRemTransformer1 | |
34 | * @see DRemTransformer12 | |
35 | */ | |
36 | 1 | public class DRemTransformer2 implements InstructionsTransformer { |
37 | ||
38 | /** Holder for the singleton instance.*/ | |
39 | 1 | private static class LazyHolder { |
40 | /** The singleton instance. */ | |
41 | 1 | private static final InstructionsTransformer INSTANCE = new DRemTransformer2(); |
42 | } | |
43 | ||
44 | /** Hidden constructor. | |
45 | */ | |
46 | 1 | private DRemTransformer2() { |
47 | 1 | } |
48 | ||
49 | /** Get the singleton instance. | |
50 | * <p>We use here the Initialization on Demand Holder idiom.</p> | |
51 | * @return the singleton instance | |
52 | */ | |
53 | public static InstructionsTransformer getInstance() { | |
54 | 1 | return LazyHolder.INSTANCE; |
55 | } | |
56 | ||
57 | /** {@inheritDoc} */ | |
58 | public InsnList getReplacement(final AbstractInsnNode insn, | |
59 | final MethodDifferentiator methodDifferentiator) | |
60 | throws DifferentiationException { | |
61 | ||
62 | 1 | final int tmp1 = methodDifferentiator.getTmp(1); |
63 | 1 | final int tmp2 = methodDifferentiator.getTmp(2); |
64 | 1 | final int tmp3 = methodDifferentiator.getTmp(3); |
65 | 1 | final InsnList list = new InsnList(); |
66 | ||
67 | // operand stack initial state: a, b0, b1 | |
68 | 1 | list.add(new VarInsnNode(Opcodes.DSTORE, tmp1)); // => a, b0 |
69 | 1 | list.add(new VarInsnNode(Opcodes.DSTORE, tmp2)); // => a |
70 | 1 | list.add(new VarInsnNode(Opcodes.DSTORE, tmp3)); // => |
71 | 1 | list.add(new VarInsnNode(Opcodes.DLOAD, tmp3)); // => a |
72 | 1 | list.add(new VarInsnNode(Opcodes.DLOAD, tmp2)); // => a, b0 |
73 | 1 | list.add(new InsnNode(Opcodes.DREM)); // => a%b0 |
74 | 1 | list.add(new InsnNode(Opcodes.DUP2)); // => a%b0, a%b0 |
75 | 1 | list.add(new VarInsnNode(Opcodes.DLOAD, tmp3)); // => a%b0, a%b0, a |
76 | 1 | list.add(new InsnNode(Opcodes.DSUB)); // => a%b0, a%b0-a |
77 | 1 | list.add(new VarInsnNode(Opcodes.DLOAD, tmp2)); // => a%b0, a%b0-a, b0 |
78 | 1 | list.add(new InsnNode(Opcodes.DDIV)); // => a%b0, -q |
79 | 1 | list.add(new VarInsnNode(Opcodes.DLOAD, tmp1)); // => a%b0, -q, b1 |
80 | 1 | list.add(new InsnNode(Opcodes.DMUL)); // => a%b0, -q*b1 |
81 | ||
82 | 1 | return list; |
83 | ||
84 | } | |
85 | ||
86 | } |