1 /* 2 * Copyright (c) 2009, 2011, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 package org.graalvm.compiler.bytecode; 24 25 /** 26 * A utility for processing {@link Bytecodes#LOOKUPSWITCH} bytecodes. 27 */ 28 public class BytecodeLookupSwitch extends BytecodeSwitch { 29 30 private static final int OFFSET_TO_NUMBER_PAIRS = 4; 31 private static final int OFFSET_TO_FIRST_PAIR_MATCH = 8; 32 private static final int OFFSET_TO_FIRST_PAIR_OFFSET = 12; 33 private static final int PAIR_SIZE = 8; 34 35 /** 36 * Constructor for a {@link BytecodeStream}. 37 * 38 * @param stream the {@code BytecodeStream} containing the switch instruction 39 * @param bci the index in the stream of the switch instruction 40 */ 41 public BytecodeLookupSwitch(BytecodeStream stream, int bci) { 42 super(stream, bci); 43 } 44 45 @Override 46 public int offsetAt(int i) { 47 return stream.readInt(alignedBci + OFFSET_TO_FIRST_PAIR_OFFSET + PAIR_SIZE * i); 48 } 49 50 @Override 51 public int keyAt(int i) { 52 return stream.readInt(alignedBci + OFFSET_TO_FIRST_PAIR_MATCH + PAIR_SIZE * i); 53 } 54 55 @Override 56 public int numberOfCases() { 57 return stream.readInt(alignedBci + OFFSET_TO_NUMBER_PAIRS); 58 } 59 60 @Override 61 public int size() { 62 return alignedBci + OFFSET_TO_FIRST_PAIR_MATCH + PAIR_SIZE * numberOfCases() - bci; 63 } 64 }