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8030212: Several api.java.util.stream tests got "NaN" value instead of "Infinity" or "-Infinity"

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Reviewed-by: mduigou, psandoz
This commit is contained in:
Joe Darcy 2014-01-03 10:38:23 -08:00
parent 456defc468
commit 398131c8a7
4 changed files with 126 additions and 32 deletions
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13
jdk/src/share/classes/java/util/DoubleSummaryStatistics.java
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@ -64,6 +64,7 @@ public class DoubleSummaryStatistics implements DoubleConsumer {
private long count;
private double sum;
private double sumCompensation; // Low order bits of sum
private double simpleSum; // Used to compute right sum for non-finite inputs
private double min = Double.POSITIVE_INFINITY;
private double max = Double.NEGATIVE_INFINITY;
@ -82,6 +83,7 @@ public class DoubleSummaryStatistics implements DoubleConsumer {
@Override
public void accept(double value) {
++count;
simpleSum += value;
sumWithCompensation(value);
min = Math.min(min, value);
max = Math.max(max, value);
@ -96,6 +98,7 @@ public class DoubleSummaryStatistics implements DoubleConsumer {
*/
public void combine(DoubleSummaryStatistics other) {
count += other.count;
simpleSum += other.simpleSum;
sumWithCompensation(other.sum);
sumWithCompensation(other.sumCompensation);
min = Math.min(min, other.min);
@ -147,7 +150,15 @@ public class DoubleSummaryStatistics implements DoubleConsumer {
*/
public final double getSum() {
// Better error bounds to add both terms as the final sum
return sum + sumCompensation;
double tmp = sum + sumCompensation;
if (Double.isNaN(tmp) && Double.isInfinite(simpleSum))
// If the compensated sum is spuriously NaN from
// accumulating one or more same-signed infinite values,
// return the correctly-signed infinity stored in
// simpleSum.
return simpleSum;
else
return tmp;
}
/**

43
jdk/src/share/classes/java/util/stream/Collectors.java
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@ -507,16 +507,20 @@ public final class Collectors {
summingDouble(ToDoubleFunction<? super T> mapper) {
/*
* In the arrays allocated for the collect operation, index 0
* holds the high-order bits of the running sum and index 1
* holds the low-order bits of the sum computed via
* compensated summation.
* holds the high-order bits of the running sum, index 1 holds
* the low-order bits of the sum computed via compensated
* summation, and index 2 holds the simple sum used to compute
* the proper result if the stream contains infinite values of
* the same sign.
*/
return new CollectorImpl<>(
() -> new double[2],
(a, t) -> { sumWithCompensation(a, mapper.applyAsDouble(t)); },
(a, b) -> { sumWithCompensation(a, b[0]); return sumWithCompensation(a, b[1]); },
// Better error bounds to add both terms as the final sum
a -> a[0] + a[1],
() -> new double[3],
(a, t) -> { sumWithCompensation(a, mapper.applyAsDouble(t));
a[2] += mapper.applyAsDouble(t);},
(a, b) -> { sumWithCompensation(a, b[0]);
a[2] += b[2];
return sumWithCompensation(a, b[1]); },
a -> computeFinalSum(a),
CH_NOID);
}
@ -540,6 +544,20 @@ public final class Collectors {
return intermediateSum;
}
/**
* If the compensated sum is spuriously NaN from accumulating one
* or more same-signed infinite values, return the
* correctly-signed infinity stored in the simple sum.
*/
static double computeFinalSum(double[] summands) {
// Better error bounds to add both terms as the final sum
double tmp = summands[0] + summands[1];
double simpleSum = summands[summands.length - 1];
if (Double.isNaN(tmp) && Double.isInfinite(simpleSum))
return simpleSum;
else
return tmp;
}
/**
* Returns a {@code Collector} that produces the arithmetic mean of an integer-valued
@ -608,11 +626,10 @@ public final class Collectors {
* summation, and index 2 holds the number of values seen.
*/
return new CollectorImpl<>(
() -> new double[3],
(a, t) -> { sumWithCompensation(a, mapper.applyAsDouble(t)); a[2]++; },
(a, b) -> { sumWithCompensation(a, b[0]); sumWithCompensation(a, b[1]); a[2] += b[2]; return a; },
// Better error bounds to add both terms as the final sum to compute average
a -> (a[2] == 0) ? 0.0d : ((a[0] + a[1]) / a[2]),
() -> new double[4],
(a, t) -> { sumWithCompensation(a, mapper.applyAsDouble(t)); a[2]++; a[3]+= mapper.applyAsDouble(t);},
(a, b) -> { sumWithCompensation(a, b[0]); sumWithCompensation(a, b[1]); a[2] += b[2]; a[3] += b[3]; return a; },
a -> (a[2] == 0) ? 0.0d : (computeFinalSum(a) / a[2]),
CH_NOID);
}

25
jdk/src/share/classes/java/util/stream/DoublePipeline.java
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@ -379,21 +379,24 @@ abstract class DoublePipeline<E_IN>
public final double sum() {
/*
* In the arrays allocated for the collect operation, index 0
* holds the high-order bits of the running sum and index 1
* holds the low-order bits of the sum computed via
* compensated summation.
* holds the high-order bits of the running sum, index 1 holds
* the low-order bits of the sum computed via compensated
* summation, and index 2 holds the simple sum used to compute
* the proper result if the stream contains infinite values of
* the same sign.
*/
double[] summation = collect(() -> new double[2],
double[] summation = collect(() -> new double[3],
(ll, d) -> {
Collectors.sumWithCompensation(ll, d);
ll[2] += d;
},
(ll, rr) -> {
Collectors.sumWithCompensation(ll, rr[0]);
Collectors.sumWithCompensation(ll, rr[1]);
ll[2] += rr[2];
});
// Better error bounds to add both terms as the final sum
return summation[0] + summation[1];
return Collectors.computeFinalSum(summation);
}
@Override
@ -421,21 +424,23 @@ abstract class DoublePipeline<E_IN>
* In the arrays allocated for the collect operation, index 0
* holds the high-order bits of the running sum, index 1 holds
* the low-order bits of the sum computed via compensated
* summation, and index 2 holds the number of values seen.
* summation, index 2 holds the number of values seen, index 3
* holds the simple sum.
*/
double[] avg = collect(() -> new double[3],
double[] avg = collect(() -> new double[4],
(ll, d) -> {
ll[2]++;
Collectors.sumWithCompensation(ll, d);
ll[3] += d;
},
(ll, rr) -> {
Collectors.sumWithCompensation(ll, rr[0]);
Collectors.sumWithCompensation(ll, rr[1]);
ll[2] += rr[2];
ll[3] += rr[3];
});
return avg[2] > 0
// Better error bounds to add both terms as the final sum to compute average
? OptionalDouble.of((avg[0] + avg[1]) / avg[2])
? OptionalDouble.of(Collectors.computeFinalSum(avg) / avg[2])
: OptionalDouble.empty();
}

77
jdk/test/java/util/stream/TestDoubleSumAverage.java
View File

@ -25,23 +25,35 @@ import java.util.*;
import java.util.function.*;
import java.util.stream.*;
import static java.lang.Double.*;
/*
* @test
* @bug 8006572
* @bug 8006572 8030212
* @summary Test for use of non-naive summation in stream-related sum and average operations.
*/
public class TestDoubleSumAverage {
public static void main(String... args) {
int failures = 0;
failures += testForCompenstation();
failures += testZeroAverageOfNonEmptyStream();
failures += testForCompenstation();
failures += testNonfiniteSum();
if (failures > 0) {
throw new RuntimeException("Found " + failures + " numerical failure(s).");
}
}
/**
* Test to verify that a non-empty stream with a zero average is non-empty.
*/
private static int testZeroAverageOfNonEmptyStream() {
Supplier<DoubleStream> ds = () -> DoubleStream.iterate(0.0, e -> 0.0).limit(10);
return compareUlpDifference(0.0, ds.get().average().getAsDouble(), 0);
}
/**
* Compute the sum and average of a sequence of double values in
* various ways and report an error if naive summation is used.
@ -83,19 +95,68 @@ public class TestDoubleSumAverage {
return failures;
}
/**
* Test to verify that a non-empty stream with a zero average is non-empty.
*/
private static int testZeroAverageOfNonEmptyStream() {
Supplier<DoubleStream> ds = () -> DoubleStream.iterate(0.0, e -> 0.0).limit(10);
private static int testNonfiniteSum() {
int failures = 0;
return compareUlpDifference(0.0, ds.get().average().getAsDouble(), 0);
Map<Supplier<DoubleStream>, Double> testCases = new LinkedHashMap<>();
testCases.put(() -> DoubleStream.of(MAX_VALUE, MAX_VALUE), POSITIVE_INFINITY);
testCases.put(() -> DoubleStream.of(-MAX_VALUE, -MAX_VALUE), NEGATIVE_INFINITY);
testCases.put(() -> DoubleStream.of(1.0d, POSITIVE_INFINITY, 1.0d), POSITIVE_INFINITY);
testCases.put(() -> DoubleStream.of(POSITIVE_INFINITY), POSITIVE_INFINITY);
testCases.put(() -> DoubleStream.of(POSITIVE_INFINITY, POSITIVE_INFINITY), POSITIVE_INFINITY);
testCases.put(() -> DoubleStream.of(POSITIVE_INFINITY, POSITIVE_INFINITY, 0.0), POSITIVE_INFINITY);
testCases.put(() -> DoubleStream.of(1.0d, NEGATIVE_INFINITY, 1.0d), NEGATIVE_INFINITY);
testCases.put(() -> DoubleStream.of(NEGATIVE_INFINITY), NEGATIVE_INFINITY);
testCases.put(() -> DoubleStream.of(NEGATIVE_INFINITY, NEGATIVE_INFINITY), NEGATIVE_INFINITY);
testCases.put(() -> DoubleStream.of(NEGATIVE_INFINITY, NEGATIVE_INFINITY, 0.0), NEGATIVE_INFINITY);
testCases.put(() -> DoubleStream.of(1.0d, NaN, 1.0d), NaN);
testCases.put(() -> DoubleStream.of(NaN), NaN);
testCases.put(() -> DoubleStream.of(1.0d, NEGATIVE_INFINITY, POSITIVE_INFINITY, 1.0d), NaN);
testCases.put(() -> DoubleStream.of(1.0d, POSITIVE_INFINITY, NEGATIVE_INFINITY, 1.0d), NaN);
testCases.put(() -> DoubleStream.of(POSITIVE_INFINITY, NaN), NaN);
testCases.put(() -> DoubleStream.of(NEGATIVE_INFINITY, NaN), NaN);
testCases.put(() -> DoubleStream.of(NaN, POSITIVE_INFINITY), NaN);
testCases.put(() -> DoubleStream.of(NaN, NEGATIVE_INFINITY), NaN);
for(Map.Entry<Supplier<DoubleStream>, Double> testCase : testCases.entrySet()) {
Supplier<DoubleStream> ds = testCase.getKey();
double expected = testCase.getValue();
DoubleSummaryStatistics stats = ds.get().collect(DoubleSummaryStatistics::new,
DoubleSummaryStatistics::accept,
DoubleSummaryStatistics::combine);
failures += compareUlpDifference(expected, stats.getSum(), 0);
failures += compareUlpDifference(expected, stats.getAverage(), 0);
failures += compareUlpDifference(expected, ds.get().sum(), 0);
failures += compareUlpDifference(expected, ds.get().average().getAsDouble(), 0);
failures += compareUlpDifference(expected, ds.get().boxed().collect(Collectors.summingDouble(d -> d)), 0);
failures += compareUlpDifference(expected, ds.get().boxed().collect(Collectors.averagingDouble(d -> d)), 0);
}
return failures;
}
/**
* Compute the ulp difference of two double values and compare against an error threshold.
*/
private static int compareUlpDifference(double expected, double computed, double threshold) {
if (!Double.isFinite(expected)) {
// Handle NaN and infinity cases
if (Double.compare(expected, computed) == 0)
return 0;
else {
System.err.printf("Unexpected sum, %g rather than %g.%n",
computed, expected);
return 1;
}
}
double ulpDifference = Math.abs(expected - computed) / Math.ulp(expected);
if (ulpDifference > threshold) {