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. 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))); > > -- http://people.apache.org/~britter/ http://www.systemoutprintln.de/ http://twitter.com/BenediktRitter http://github.com/britter
