1 /* 2 * Copyright (c) 2015, 2015, 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.lir.alloc.trace.lsra; 24 25 /** 26 * Represents a range of integers from a start (inclusive) to an end (exclusive). 27 */ 28 final class FixedRange { 29 30 public static final FixedRange EndMarker = new FixedRange(Integer.MAX_VALUE, Integer.MAX_VALUE, null); 31 32 /** 33 * The start of the range, inclusive. 34 */ 35 public int from; 36 37 /** 38 * The end of the range, exclusive. 39 */ 40 public int to; 41 42 /** 43 * A link to allow the range to be put into a singly linked list. 44 */ 45 public FixedRange next; 46 47 boolean intersects(TraceInterval i) { 48 return intersectsAt(i) != -1; 49 } 50 51 /** 52 * Creates a new range. 53 * 54 * @param from the start of the range, inclusive 55 * @param to the end of the range, exclusive 56 * @param next link to the next range in a linked list 57 */ 58 FixedRange(int from, int to, FixedRange next) { 59 this.from = from; 60 this.to = to; 61 this.next = next; 62 } 63 64 int intersectsAt(TraceInterval other) { 65 FixedRange range = this; 66 assert other != null : "null ranges not allowed"; 67 assert range != EndMarker && other != TraceInterval.EndMarker : "empty ranges not allowed"; 68 int intervalFrom = other.from(); 69 int intervalTo = other.to(); 70 71 do { 72 if (range.from < intervalFrom) { 73 if (range.to <= intervalFrom) { 74 range = range.next; 75 if (range == EndMarker) { 76 return -1; 77 } 78 } else { 79 return intervalFrom; 80 } 81 } else { 82 if (intervalFrom < range.from) { 83 if (intervalTo <= range.from) { 84 return -1; 85 } 86 return range.from; 87 } else { 88 assert range.from == intervalFrom; 89 if (range.from == range.to) { 90 range = range.next; 91 if (range == EndMarker) { 92 return -1; 93 } 94 } else { 95 if (intervalFrom == intervalTo) { 96 return -1; 97 } 98 return range.from; 99 } 100 } 101 } 102 } while (true); 103 } 104 105 @Override 106 public String toString() { 107 return "[" + from + ", " + to + "]"; 108 } 109 }