WALA/com.ibm.wala.util/src/com/ibm/wala/dataflow/graph/BitVectorKillGen.java

82 lines
2.3 KiB
Java

/*******************************************************************************
* 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;
/**
* Operator OUT = (IN - kill) U gen
*/
public class BitVectorKillGen extends UnaryOperator<BitVectorVariable> {
private final BitVectorIntSet kill;
private final BitVectorIntSet gen;
public BitVectorKillGen(BitVector kill, BitVector gen) {
if (kill == null) {
throw new IllegalArgumentException("null kill");
}
if (gen == null) {
throw new IllegalArgumentException("null gen");
}
this.kill = new BitVectorIntSet(kill);
this.gen = new BitVectorIntSet(gen);
}
@Override
public byte evaluate(BitVectorVariable lhs, BitVectorVariable rhs) throws IllegalArgumentException {
if (rhs == null) {
throw new IllegalArgumentException("rhs == null");
}
if (lhs == null) {
throw new IllegalArgumentException("lhs == null");
}
BitVectorVariable U = new BitVectorVariable();
BitVectorIntSet bv = new BitVectorIntSet();
if (rhs.getValue() != null) {
bv.addAll(rhs.getValue());
}
bv.removeAll(kill);
bv.addAll(gen);
U.addAll(bv.getBitVector());
if (!lhs.sameValue(U)) {
lhs.copyState(U);
return CHANGED;
} else {
return NOT_CHANGED;
}
}
@Override
public String toString() {
return "GenKill";
}
@Override
public int hashCode() {
return 9901 * kill.hashCode() + 1213 * gen.hashCode();
}
@Override
public boolean equals(Object o) {
if (o instanceof BitVectorKillGen) {
BitVectorKillGen other = (BitVectorKillGen) o;
return kill.sameValue(other.kill) && gen.sameValue(other.gen);
} else {
return false;
}
}
}