/*******************************************************************************
* Copyright (c) 2002 - 2006 IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package com.ibm.wala.dataflow.graph;
import com.ibm.wala.fixpoint.BitVectorVariable;
import com.ibm.wala.fixpoint.UnaryOperator;
import com.ibm.wala.util.intset.BitVector;
import com.ibm.wala.util.intset.BitVectorIntSet;
import com.ibm.wala.util.intset.IntSet;
/**
* Operator OUT = IN - filterSet
*/
public class BitVectorFilter extends UnaryOperator<BitVectorVariable> {
private final BitVectorIntSet mask;
public BitVectorFilter(BitVector mask) {
if (mask == null) {
throw new IllegalArgumentException("null mask");
}
this.mask = new BitVectorIntSet(mask);
}
@Override
public byte evaluate(BitVectorVariable lhs, BitVectorVariable rhs) throws IllegalArgumentException {
if (rhs == null) {
throw new IllegalArgumentException("rhs == null");
}
BitVectorVariable U = new BitVectorVariable();
U.copyState(lhs);
IntSet r = rhs.getValue();
if (r == null) {
return NOT_CHANGED;
}
BitVectorIntSet rr = new BitVectorIntSet();
rr.addAll(r);
rr.removeAll(mask);
System.err.println("adding " + rr + " to " + lhs);
U.addAll(rr.getBitVector());
if (!lhs.sameValue(U)) {
lhs.copyState(U);
return CHANGED;
} else {
return NOT_CHANGED;
}
}
/**
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
return "U - " + mask;
}
@Override
public int hashCode() {
return 29 * mask.hashCode();
}
@Override
public boolean equals(Object o) {
if (o instanceof BitVectorFilter) {
BitVectorFilter other = (BitVectorFilter) o;
return mask.equals(other.mask);
} else {
return false;
}
}
}