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.instructions;
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
29 /** Differentiation transformer for DCMPx instructions.
30 * @version $Id$
31 */
32 public class DcmpTransformer implements InstructionsTransformer {
33
34 /** Name of the {@link org.apache.commons.math3.analysis.differentiation.DerivativeStructure} method corresponding to the value getter. */
35 private static final String VALUE_GETTER_METHOD = "getValue";
36
37 /** Indicator for top stack element conversion. */
38 private final boolean stack0Converted;
39
40 /** Indicator for next to top stack element conversion. */
41 private final boolean stack1Converted;
42
43 /** Simple constructor.
44 * @param stack0Converted if true, the top level stack element has already been converted
45 * @param stack1Converted if true, the next to top level stack element has already been converted
46 */
47 public DcmpTransformer(final boolean stack0Converted, final boolean stack1Converted) {
48 this.stack0Converted = stack0Converted;
49 this.stack1Converted = stack1Converted;
50 }
51
52 /** {@inheritDoc} */
53 public InsnList getReplacement(final AbstractInsnNode insn,
54 final MethodDifferentiator methodDifferentiator)
55 throws DifferentiationException {
56 final InsnList list = new InsnList();
57
58 if (stack1Converted) {
59 if (stack0Converted) {
60 // operand stack initial state: ds_a, ds_b
61 list.add(new InsnNode(Opcodes.SWAP)); // => ds_b, ds_a
62 list.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, DS_TYPE.getInternalName(),
63 VALUE_GETTER_METHOD,
64 Type.getMethodDescriptor(Type.DOUBLE_TYPE))); // => ds_b, a0
65 list.add(new InsnNode(Opcodes.DUP2_X2)); // => a0, ds_b, a0
66 list.add(new InsnNode(Opcodes.POP2)); // => a0, ds_b
67 list.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, DS_TYPE.getInternalName(),
68 VALUE_GETTER_METHOD,
69 Type.getMethodDescriptor(Type.DOUBLE_TYPE))); // => a0, b0
70 } else {
71 // operand stack initial state: ds_a, b0
72 list.add(new InsnNode(Opcodes.DUP2_X2)); // => b0, ds_a, b0
73 list.add(new InsnNode(Opcodes.POP2)); // => b0, ds_a
74 list.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, DS_TYPE.getInternalName(),
75 VALUE_GETTER_METHOD,
76 Type.getMethodDescriptor(Type.DOUBLE_TYPE))); // => b0, a0
77 list.add(new InsnNode(Opcodes.DUP2_X2)); // => a0, b0, a0
78 list.add(new InsnNode(Opcodes.POP2)); // => a0, b0
79 }
80 } else {
81 // operand stack initial state: a, ds_b
82 list.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, DS_TYPE.getInternalName(),
83 VALUE_GETTER_METHOD,
84 Type.getMethodDescriptor(Type.DOUBLE_TYPE))); // => a0, b0
85 }
86
87 list.add(new InsnNode(insn.getOpcode())); // => bool
88
89 return list;
90
91 }
92
93 }