WALA/com.ibm.wala.shrike/src/com/ibm/wala/shrikeBT/ComparisonInstruction.java

133 lines
3.6 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.shrikeBT;
/**
* This class represents comparisons between floats, longs and doubles.
*/
final public class ComparisonInstruction extends Instruction implements IComparisonInstruction {
protected ComparisonInstruction(short opcode) {
super(opcode);
}
private final static ComparisonInstruction preallocatedLCMP = new ComparisonInstruction(OP_lcmp);
private final static ComparisonInstruction[] preallocatedFloatingCompares = preallocateFloatingCompares();
private static ComparisonInstruction[] preallocateFloatingCompares() {
ComparisonInstruction[] r = new ComparisonInstruction[OP_dcmpg - OP_fcmpl + 1];
for (short i = OP_fcmpl; i <= OP_dcmpg; i++) {
r[i - OP_fcmpl] = new ComparisonInstruction(i);
}
return r;
}
public static ComparisonInstruction make(String type, Operator operator) throws IllegalArgumentException {
int t = Util.getTypeIndex(type);
switch (t) {
case TYPE_long_index:
if (operator != Operator.CMP) {
throw new IllegalArgumentException("Operator " + operator + " is not a valid comparison operator for longs");
} else {
return preallocatedLCMP;
}
case TYPE_float_index:
case TYPE_double_index:
if (operator == Operator.CMP) {
throw new IllegalArgumentException("Operator " + operator + " is not a valid comparison operator for floating point values");
} else {
return preallocatedFloatingCompares[(operator.ordinal() - Operator.CMPL.ordinal()) + (t - TYPE_float_index) * 2];
}
default:
throw new IllegalArgumentException("Type " + type + " cannot be compared");
}
}
@Override
public boolean equals(Object o) {
if (o instanceof ComparisonInstruction) {
ComparisonInstruction i = (ComparisonInstruction) o;
return i.opcode == opcode;
} else {
return false;
}
}
/**
* @return OPR_cmp (for long), OPR_cmpl, or OPR_cmpg (for float and double)
*/
@Override
public Operator getOperator() {
switch (opcode) {
case OP_lcmp:
return Operator.CMP;
case OP_fcmpl:
case OP_dcmpl:
return Operator.CMPL;
case OP_dcmpg:
case OP_fcmpg:
return Operator.CMPG;
default:
throw new Error("Unknown opcode");
}
}
@Override
public String getType() {
switch (opcode) {
case OP_lcmp:
return TYPE_long;
case OP_fcmpg:
case OP_fcmpl:
return TYPE_float;
case OP_dcmpl:
case OP_dcmpg:
return TYPE_double;
default:
throw new Error("Unknown opcode");
}
}
@Override
public int hashCode() {
return opcode + 1391901;
}
@Override
public int getPoppedCount() {
return 2;
}
@Override
public String getPushedType(String[] types) {
return Constants.TYPE_boolean;
}
@Override
public byte getPushedWordSize() {
return 1;
}
@Override
public void visit(IInstruction.Visitor v) throws NullPointerException {
v.visitComparison(this);
}
@Override
public String toString() {
return "Comparison(" + getType() + "," + getOperator() + ")";
}
@Override
public boolean isPEI() {
return false;
}
}