1 /* 2 * Copyright (c) 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.java; 24 25 public class JsrScope { 26 27 public static final JsrScope EMPTY_SCOPE = new JsrScope(); 28 29 private final long scope; 30 31 private JsrScope(long scope) { 32 this.scope = scope; 33 } 34 35 public JsrScope() { 36 this.scope = 0; 37 } 38 39 public int nextReturnAddress() { 40 return (int) (scope & 0xffff); 41 } 42 43 public JsrScope push(int jsrReturnBci) { 44 if ((scope & 0xffff000000000000L) != 0) { 45 throw new JsrNotSupportedBailout("only four jsr nesting levels are supported"); 46 } 47 return new JsrScope((scope << 16) | jsrReturnBci); 48 } 49 50 public boolean isEmpty() { 51 return scope == 0; 52 } 53 54 public boolean isPrefixOf(JsrScope other) { 55 return (scope & other.scope) == scope; 56 } 57 58 public JsrScope pop() { 59 return new JsrScope(scope >>> 16); 60 } 61 62 @Override 63 public int hashCode() { 64 return (int) (scope ^ (scope >>> 32)); 65 } 66 67 @Override 68 public boolean equals(Object obj) { 69 if (this == obj) { 70 return true; 71 } 72 return obj != null && getClass() == obj.getClass() && scope == ((JsrScope) obj).scope; 73 } 74 75 @Override 76 public String toString() { 77 StringBuilder sb = new StringBuilder(); 78 long tmp = scope; 79 sb.append(" ["); 80 while (tmp != 0) { 81 sb.append(", ").append(tmp & 0xffff); 82 tmp = tmp >>> 16; 83 } 84 sb.append(']'); 85 return sb.toString(); 86 } 87 }