| /* |
| * Copyright (c) 2009, 2011, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| package org.graalvm.compiler.lir.alloc.lsra; |
| |
| /** |
| * Represents a range of integers from a start (inclusive) to an end (exclusive. |
| */ |
| public final class Range { |
| |
| public static final Range EndMarker = new Range(Integer.MAX_VALUE, Integer.MAX_VALUE, null); |
| |
| /** |
| * The start of the range, inclusive. |
| */ |
| public int from; |
| |
| /** |
| * The end of the range, exclusive. |
| */ |
| public int to; |
| |
| /** |
| * A link to allow the range to be put into a singly linked list. |
| */ |
| public Range next; |
| |
| boolean intersects(Range r) { |
| return intersectsAt(r) != -1; |
| } |
| |
| /** |
| * Creates a new range. |
| * |
| * @param from the start of the range, inclusive |
| * @param to the end of the range, exclusive |
| * @param next link to the next range in a linked list |
| */ |
| Range(int from, int to, Range next) { |
| this.from = from; |
| this.to = to; |
| this.next = next; |
| } |
| |
| int intersectsAt(Range other) { |
| Range r1 = this; |
| Range r2 = other; |
| |
| assert r2 != null : "null ranges not allowed"; |
| assert r1 != EndMarker && r2 != EndMarker : "empty ranges not allowed"; |
| |
| do { |
| if (r1.from < r2.from) { |
| if (r1.to <= r2.from) { |
| r1 = r1.next; |
| if (r1 == EndMarker) { |
| return -1; |
| } |
| } else { |
| return r2.from; |
| } |
| } else { |
| if (r2.from < r1.from) { |
| if (r2.to <= r1.from) { |
| r2 = r2.next; |
| if (r2 == EndMarker) { |
| return -1; |
| } |
| } else { |
| return r1.from; |
| } |
| } else { // r1.from() == r2.from() |
| if (r1.from == r1.to) { |
| r1 = r1.next; |
| if (r1 == EndMarker) { |
| return -1; |
| } |
| } else { |
| if (r2.from == r2.to) { |
| r2 = r2.next; |
| if (r2 == EndMarker) { |
| return -1; |
| } |
| } else { |
| return r1.from; |
| } |
| } |
| } |
| } |
| } while (true); |
| } |
| |
| @Override |
| public String toString() { |
| return "[" + from + ", " + to + "]"; |
| } |
| } |