/*
 * Copyright  2000-2004 The Apache Software Foundation
 *
 *  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 org.apache.bcel.generic;

/**
 * LDC2_W - Push long or double from constant pool
 * 
 * <PRE>
 * Stack: ... -&gt; ..., item.word1, item.word2
 * </PRE>
 * 
 * @version $Id: LDC2_W.java 386056 2006-03-15 11:31:56Z tcurdt $
 * @author <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
 */
public class LDC2_W extends CPInstruction implements PushInstruction,
		TypedInstruction {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	/**
	 * Empty constructor needed for the Class.newInstance() statement in
	 * Instruction.readInstruction(). Not to be used otherwise.
	 */
	LDC2_W() {
	}

	public LDC2_W(int index) {
		super(org.apache.bcel.Constants.LDC2_W, index);
	}

	@Override
	public Type getType(ConstantPoolGen cpg) {
		switch (cpg.getConstantPool().getConstant(index).getTag()) {
		case org.apache.bcel.Constants.CONSTANT_Long:
			return Type.LONG;
		case org.apache.bcel.Constants.CONSTANT_Double:
			return Type.DOUBLE;
		default: // Never reached
			throw new RuntimeException("Unknown constant type " + opcode);
		}
	}

	public Number getValue(ConstantPoolGen cpg) {
		org.apache.bcel.classfile.Constant c = cpg.getConstantPool()
				.getConstant(index);
		switch (c.getTag()) {
		case org.apache.bcel.Constants.CONSTANT_Long:
			return new Long(
					((org.apache.bcel.classfile.ConstantLong) c).getBytes());
		case org.apache.bcel.Constants.CONSTANT_Double:
			return new Double(
					((org.apache.bcel.classfile.ConstantDouble) c).getBytes());
		default: // Never reached
			throw new RuntimeException("Unknown or invalid constant type at "
					+ index);
		}
	}

	/**
	 * Call corresponding visitor method(s). The order is: Call visitor methods
	 * of implemented interfaces first, then call methods according to the class
	 * hierarchy in descending order, i.e., the most specific visitXXX() call
	 * comes last.
	 * 
	 * @param v
	 *            Visitor object
	 */
	@Override
	public void accept(Visitor v) {
		v.visitStackProducer(this);
		v.visitPushInstruction(this);
		v.visitTypedInstruction(this);
		v.visitCPInstruction(this);
		v.visitLDC2_W(this);
	}
}
