/*
* Copyright (c) 2014, 2018, 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.dfa;
import java.util.ArrayDeque;
import java.util.BitSet;
import java.util.Collection;
import org.graalvm.compiler.core.common.cfg.AbstractBlockBase;
Ensures that an element is only in the worklist once.
/**
* Ensures that an element is only in the worklist once.
*
*/
class UniqueWorkList extends ArrayDeque<AbstractBlockBase<?>> {
private static final long serialVersionUID = 8009554570990975712L;
BitSet valid;
UniqueWorkList(int size) {
this.valid = new BitSet(size);
}
@Override
public AbstractBlockBase<?> poll() {
AbstractBlockBase<?> result = super.poll();
if (result != null) {
valid.set(result.getId(), false);
}
return result;
}
@Override
public boolean add(AbstractBlockBase<?> pred) {
if (!valid.get(pred.getId())) {
valid.set(pred.getId(), true);
return super.add(pred);
}
return false;
}
@Override
public boolean addAll(Collection<? extends AbstractBlockBase<?>> collection) {
boolean changed = false;
for (AbstractBlockBase<?> element : collection) {
if (!valid.get(element.getId())) {
valid.set(element.getId(), true);
super.add(element);
changed = true;
}
}
return changed;
}
}