Java tutorial
/* * Copyright (c) 2009-2012 Panxiaobo * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.googlecode.dex2jar.asm; import org.objectweb.asm.MethodAdapter; import org.objectweb.asm.MethodVisitor; import org.objectweb.asm.Opcodes; /** * @author <a href="mailto:pxb1988@gmail.com">Panxiaobo</a> * @version $Rev$ */ public class LdcOptimizeAdapter extends MethodAdapter implements Opcodes { /** * @param mv */ public LdcOptimizeAdapter(MethodVisitor mv) { super(mv); } /* * (non-Javadoc) * * @see org.objectweb.asm.MethodAdapter#visitLdcInsn(java.lang.Object) */ @Override public void visitLdcInsn(Object cst) { if (cst == null) { this.visitInsn(ACONST_NULL); } else if (cst instanceof Integer) { int value = (Integer) cst; if (value >= -1 && value <= 5) { super.visitInsn(ICONST_0 + value); } else if (value <= Byte.MAX_VALUE && value >= Byte.MIN_VALUE) { super.visitIntInsn(BIPUSH, value); } else if (value <= Short.MAX_VALUE && value >= Short.MIN_VALUE) { super.visitIntInsn(SIPUSH, value); } else { super.visitLdcInsn(cst); } } else if (cst instanceof Long) { long value = (Long) cst; if (value == 0L || value == 1L) { super.visitInsn(LCONST_0 + ((int) value)); } else { super.visitLdcInsn(cst); } } else if (cst instanceof Float) { float value = (Float) cst; if (value == 0.0F) { super.visitInsn(FCONST_0); } else if (value == 1.0F) { super.visitInsn(FCONST_1); } else if (value == 2.0F) { super.visitInsn(FCONST_2); } else { super.visitLdcInsn(cst); } } else if (cst instanceof Double) { double value = (Double) cst; if (value == 0.0D) { super.visitInsn(DCONST_0); } else if (value == 1.0D) { super.visitInsn(DCONST_1); } else { super.visitLdcInsn(cst); } } else { super.visitLdcInsn(cst); } } }