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Declarative Machine Learning
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.sysml.runtime.functionobjects;
import java.io.Serializable;
import org.apache.sysml.runtime.DMLRuntimeException;
import org.apache.sysml.runtime.instructions.cp.Data;
import org.apache.sysml.runtime.instructions.cp.KahanObject;
public class KahanPlus extends KahanFunction implements Serializable
{
private static final long serialVersionUID = -8338160609569967791L;
private static KahanPlus singleObj = null;
private KahanPlus() {
// nothing to do here
}
public static KahanPlus getKahanPlusFnObject() {
if ( singleObj == null )
singleObj = new KahanPlus();
return singleObj;
}
public Object clone() throws CloneNotSupportedException {
// cloning is not supported for singleton classes
throw new CloneNotSupportedException();
}
@Override
public Data execute(Data in1, double in2)
throws DMLRuntimeException
{
KahanObject kahanObj=(KahanObject)in1;
//fast path for INF/-INF in order to ensure result correctness
//(computing corrections otherwise incorrectly computes NaN)
if( Double.isInfinite(kahanObj._sum) || Double.isInfinite(in2) ) {
kahanObj.set(Double.isInfinite(in2) ? in2 : kahanObj._sum, 0);
return kahanObj;
}
//default path for any other value
double correction=in2+kahanObj._correction;
double sum=kahanObj._sum+correction;
kahanObj.set(sum, correction-(sum-kahanObj._sum)); //prevent eager JIT opt
return kahanObj;
}
@Override // in1, in2 is the sum, in3 is the correction
public Data execute(Data in1, double in2, double in3)
throws DMLRuntimeException
{
KahanObject kahanObj=(KahanObject)in1;
//fast path for INF/-INF in order to ensure result correctness
//(computing corrections otherwise incorrectly computes NaN)
if( Double.isInfinite(kahanObj._sum) || Double.isInfinite(in2) ) {
kahanObj.set(Double.isInfinite(in2) ? in2 : kahanObj._sum, 0);
return kahanObj;
}
//default path for any other value
double correction=in2+(kahanObj._correction+in3);
double sum=kahanObj._sum+correction;
kahanObj.set(sum, correction-(sum-kahanObj._sum)); //prevent eager JIT opt
return kahanObj;
}
/**
* Simplified version of execute(Data in1, double in2)
* without exception handling and casts.
*
* @param in1
* @param in2
*/
public void execute2(KahanObject in1, double in2)
{
//fast path for INF/-INF in order to ensure result correctness
//(computing corrections otherwise incorrectly computes NaN)
if( Double.isInfinite(in1._sum) || Double.isInfinite(in2) ) {
in1.set(Double.isInfinite(in2) ? in2 : in1._sum, 0);
return;
}
//default path for any other value
double correction = in2 + in1._correction;
double sum = in1._sum + correction;
in1.set(sum, correction-(sum-in1._sum)); //prevent eager JIT opt
}
}