Mercurial > hg > graal-jvmci-8
diff graal/Compiler/src/com/sun/c1x/alloc/Range.java @ 2507:9ec15d6914ca
Pull over of compiler from maxine repository.
author | Thomas Wuerthinger <thomas@wuerthinger.net> |
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date | Wed, 27 Apr 2011 11:43:22 +0200 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/graal/Compiler/src/com/sun/c1x/alloc/Range.java Wed Apr 27 11:43:22 2011 +0200 @@ -0,0 +1,119 @@ +/* + * Copyright (c) 2009, 2010, 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 com.sun.c1x.alloc; + + +/** + * Represents a range of integers from a start (inclusive) to an end (exclusive. + * + * @author Thomas Wuerthinger + */ +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 r2) { + Range r1 = this; + + 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 + "]"; + } +}