001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.commons.nabla.algorithmic.forward.functions; 018 019 import org.apache.commons.nabla.algorithmic.forward.analysis.MethodDifferentiator; 020 import org.apache.commons.nabla.core.DifferentiationException; 021 import org.objectweb.asm.Opcodes; 022 import org.objectweb.asm.tree.InsnList; 023 import org.objectweb.asm.tree.InsnNode; 024 import org.objectweb.asm.tree.MethodInsnNode; 025 import org.objectweb.asm.tree.VarInsnNode; 026 027 /** Differentiation transformer for the atan2 function invocation instructions. 028 */ 029 public class Atan2Transformer12 implements MathInvocationTransformer { 030 031 /** {@inheritDoc} */ 032 public InsnList getReplacementList(final String owner, final MethodDifferentiator methodDifferentiator) 033 throws DifferentiationException { 034 035 final int tmp1 = methodDifferentiator.getTmp(1); 036 final int tmp2 = methodDifferentiator.getTmp(2); 037 final int tmp3 = methodDifferentiator.getTmp(3); 038 final int tmp4 = methodDifferentiator.getTmp(4); 039 040 // generate differential code 041 // ... y0, y1, x0, x1 --> ... atan2(y0, x0), (x0*y1x0*y1-x1*y00)/(x0^2+y0^2) 042 final InsnList list = new InsnList(); 043 list.add(new VarInsnNode(Opcodes.DSTORE, tmp4)); // => y0, y1, x0 044 list.add(new VarInsnNode(Opcodes.DSTORE, tmp3)); // => y0, y1 045 list.add(new VarInsnNode(Opcodes.DSTORE, tmp2)); // => y0 046 list.add(new VarInsnNode(Opcodes.DSTORE, tmp1)); // => 047 list.add(new VarInsnNode(Opcodes.DLOAD, tmp1)); // => y0 048 list.add(new VarInsnNode(Opcodes.DLOAD, tmp3)); // => y0, x0 049 list.add(new MethodInsnNode(Opcodes.INVOKESTATIC, owner, "atan2", DD_RETURN_D_DESCRIPTOR)); // => atan2(y0,x0) 050 list.add(new VarInsnNode(Opcodes.DLOAD, tmp3)); // => atan2(y0,x0), x0 051 list.add(new VarInsnNode(Opcodes.DLOAD, tmp2)); // => atan2(y0,x0), x0, y1 052 list.add(new InsnNode(Opcodes.DMUL)); // => atan2(y0,x0), x0*y1 053 list.add(new VarInsnNode(Opcodes.DLOAD, tmp4)); // => atan2(y0,x0), x0*y1, x1 054 list.add(new VarInsnNode(Opcodes.DLOAD, tmp1)); // => atan2(y0,x0), x0*y1, x1, y0 055 list.add(new InsnNode(Opcodes.DMUL)); // => atan2(y0,x0), x0*y1, x1*y0 056 list.add(new InsnNode(Opcodes.DSUB)); // => atan2(y0,x0), x0*y1-x1*y0 057 list.add(new VarInsnNode(Opcodes.DLOAD, tmp3)); // => atan2(y0,x0), x0*y1-x1*y0, x0 058 list.add(new InsnNode(Opcodes.DUP2)); // => atan2(y0,x0), x0*y1-x1*y0, x0, x0 059 list.add(new InsnNode(Opcodes.DMUL)); // => atan2(y0,x0), x0*y1-x1*y0, x0^2 060 list.add(new VarInsnNode(Opcodes.DLOAD, tmp1)); // => atan2(y0,x0), x0*y1-x1*y0, x0^2, y0 061 list.add(new InsnNode(Opcodes.DUP2)); // => atan2(y0,x0), x0*y1-x1*y0, x0^2, y0, y0 062 list.add(new InsnNode(Opcodes.DMUL)); // => atan2(y0,x0), x0*y1-x1*y0, x0^2, y0^2 063 list.add(new InsnNode(Opcodes.DADD)); // => atan2(y0,x0), x0*y1-x1*y0, x0^2+y0^2 064 list.add(new InsnNode(Opcodes.DDIV)); // => atan2(y0,x0), (x0*y1-x1*y0)/(x0^2+y0^2) 065 return list; 066 067 } 068 069 }