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

69 lines
1.7 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;
/**
* Operator OUT = IN U c
*/
public class BitVectorUnionConstant extends UnaryOperator<BitVectorVariable> {
private final int c;
public BitVectorUnionConstant(int c) {
if (c < 0) {
throw new IllegalArgumentException("Invalid c: " + c);
}
this.c = c;
}
@Override
public byte evaluate(BitVectorVariable lhs, BitVectorVariable rhs) throws IllegalArgumentException {
if (lhs == null) {
throw new IllegalArgumentException("lhs == null");
}
BitVectorVariable U = new BitVectorVariable();
U.copyState(lhs);
U.addAll(rhs);
U.set(c);
if (!lhs.sameValue(U)) {
lhs.copyState(U);
return CHANGED;
} else {
return NOT_CHANGED;
}
}
@Override
public String toString() {
return "U " + c;
}
@Override
public int hashCode() {
return 9901 * c;
}
@Override
public boolean equals(Object o) {
if (o instanceof BitVectorUnionConstant) {
BitVectorUnionConstant other = (BitVectorUnionConstant)o;
return c == other.c;
} else {
return false;
}
}
}