Le 2015-05-04 14:32, Benedikt Ritter a écrit :
Hello Luc,
2015-05-04 13:43 GMT+02:00 <l...@apache.org>:
Repository: commons-math
Updated Branches:
refs/heads/master c8cb75243 -> c771c0080
Attempt to circumvent some errors which seem to be platform-dependent.
The Jenkins build often fails on code that seems to be perfectly
correct. Failures also do no always happen so they may depend on
platform. There were similar problems a few months ago that were
probably related to JIT bugs.
This fix simply tries to do the same thing as before, but with an
earlier detection of NaN in one case, and by comparing directly the
bits
representation in another case, to avoid wrong optimizations.
Project: http://git-wip-us.apache.org/repos/asf/commons-math/repo
Commit:
http://git-wip-us.apache.org/repos/asf/commons-math/commit/c771c008
Tree:
http://git-wip-us.apache.org/repos/asf/commons-math/tree/c771c008
Diff:
http://git-wip-us.apache.org/repos/asf/commons-math/diff/c771c008
Branch: refs/heads/master
Commit: c771c0080b08abd80418c4e88f1be3efec828f0a
Parents: c8cb752
Author: Luc Maisonobe <l...@apache.org>
Authored: Mon May 4 13:43:27 2015 +0200
Committer: Luc Maisonobe <l...@apache.org>
Committed: Mon May 4 13:43:27 2015 +0200
----------------------------------------------------------------------
.../org/apache/commons/math4/util/FastMath.java | 28
+++++++++-----------
.../apache/commons/math4/util/FastMathTest.java | 4 +--
2 files changed, 15 insertions(+), 17 deletions(-)
----------------------------------------------------------------------
http://git-wip-us.apache.org/repos/asf/commons-math/blob/c771c008/src/main/java/org/apache/commons/math4/util/FastMath.java
----------------------------------------------------------------------
diff --git a/src/main/java/org/apache/commons/math4/util/FastMath.java
b/src/main/java/org/apache/commons/math4/util/FastMath.java
index 24bb857..fcd03ea 100644
--- a/src/main/java/org/apache/commons/math4/util/FastMath.java
+++ b/src/main/java/org/apache/commons/math4/util/FastMath.java
@@ -315,6 +315,9 @@ public class FastMath {
/** Mask used to clear the non-sign part of a long. */
private static final long MASK_NON_SIGN_LONG =
0x7fffffffffffffffl;
+ /** Bits representation of +1.0. */
+ private static final long PLUS_ONE_BITS = 0x3ff0000000000000L;
+
/** 2^52 - double numbers this large must be integral (no
fraction)
or NaN or Infinite */
private static final double TWO_POWER_52 = 4503599627370496.0;
/** 2^53 - double numbers this large must be even. */
@@ -1468,6 +1471,10 @@ public class FastMath {
return x;
}
+ if (y != y) { // Y is NaN
It really took me some time to understand this change. How about using
Double.isNaN(double) instead? It does the same as the current code, but
reads better, IMHO.
I agree but in this huge class this is how all NaNs are detected and
there
are a bunch of such tests. I don't know the reason these existing tests
were done this way and not using Double.isNaN, it may well be
performance related.
So for this class (and this class only), I prefer to do it the same way
it
is already done a few lines above or below.
best regards,
Luc
Best regards,
Benedikt
+ return y;
+ }
+
if (x == 0) {
long bits = Double.doubleToRawLongBits(x);
if ((bits & 0x8000000000000000L) != 0) {
@@ -1485,18 +1492,13 @@ public class FastMath {
if (y < 0) {
return Double.POSITIVE_INFINITY;
- }
- if (y > 0) {
+ } else {
return 0.0;
}
- return Double.NaN;
}
if (x == Double.POSITIVE_INFINITY) {
- if (y != y) { // y is NaN
- return y;
- }
if (y < 0.0) {
return 0.0;
} else {
@@ -1505,21 +1507,17 @@ public class FastMath {
}
if (y == Double.POSITIVE_INFINITY) {
- if (x * x == 1.0) {
- return Double.NaN;
- }
-
- if (x * x > 1.0) {
+ long bitsAbsX = MASK_NON_SIGN_LONG &
Double.doubleToRawLongBits(x);
+ if (bitsAbsX > PLUS_ONE_BITS) {
return Double.POSITIVE_INFINITY;
- } else {
+ } else if (bitsAbsX < PLUS_ONE_BITS) {
return 0.0;
+ } else {
+ return Double.NaN;
}
}
if (x == Double.NEGATIVE_INFINITY) {
- if (y != y) { // y is NaN
- return y;
- }
if (y < 0) {
long yi = (long) y;
http://git-wip-us.apache.org/repos/asf/commons-math/blob/c771c008/src/test/java/org/apache/commons/math4/util/FastMathTest.java
----------------------------------------------------------------------
diff --git
a/src/test/java/org/apache/commons/math4/util/FastMathTest.java
b/src/test/java/org/apache/commons/math4/util/FastMathTest.java
index 5d36fea..06a1d07 100644
--- a/src/test/java/org/apache/commons/math4/util/FastMathTest.java
+++ b/src/test/java/org/apache/commons/math4/util/FastMathTest.java
@@ -29,8 +29,6 @@ import
org.apache.commons.math4.exception.MathArithmeticException;
import org.apache.commons.math4.random.MersenneTwister;
import org.apache.commons.math4.random.RandomGenerator;
import org.apache.commons.math4.random.Well1024a;
-import org.apache.commons.math4.util.FastMath;
-import org.apache.commons.math4.util.Precision;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Ignore;
@@ -393,6 +391,8 @@ public class FastMathTest {
Assert.assertTrue("pow(-2.0, 3.5) should be NaN",
Double.isNaN(FastMath.pow(-2.0, 3.5)));
+ Assert.assertTrue("pow(-0.0, NaN) should be NaN",
Double.isNaN(FastMath.pow(-0.0, Double.NaN)));
+
// Added tests for a 100% coverage
Assert.assertTrue("pow(+Inf, NaN) should be NaN",
Double.isNaN(FastMath.pow(Double.POSITIVE_INFINITY, Double.NaN)));
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