/*
* Copyright (c) 2015, 2015, 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
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* questions.
*/
package org.graalvm.compiler.lir.alloc.trace.lsra;
/**
* Represents a range of integers from a start (inclusive) to an end (exclusive).
*/
final class FixedRange {
public static final FixedRange EndMarker = new FixedRange(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 FixedRange next;
boolean intersects(TraceInterval i) {
return intersectsAt(i) != -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
*/
FixedRange(int from, int to, FixedRange next) {
this.from = from;
this.to = to;
this.next = next;
}
int intersectsAt(TraceInterval other) {
FixedRange range = this;
assert other != null : "null ranges not allowed";
assert range != EndMarker && other != TraceInterval.EndMarker : "empty ranges not allowed";
int intervalFrom = other.from();
int intervalTo = other.to();
do {
if (range.from < intervalFrom) {
if (range.to <= intervalFrom) {
range = range.next;
if (range == EndMarker) {
return -1;
}
} else {
return intervalFrom;
}
} else {
if (intervalFrom < range.from) {
if (intervalTo <= range.from) {
return -1;
}
return range.from;
} else {
assert range.from == intervalFrom;
if (range.from == range.to) {
range = range.next;
if (range == EndMarker) {
return -1;
}
} else {
if (intervalFrom == intervalTo) {
return -1;
}
return range.from;
}
}
}
} while (true);
}
@Override
public String toString() {
return "[" + from + ", " + to + "]";
}
}