diff options
Diffstat (limited to 'libjava/java/lang/Double.java')
-rw-r--r-- | libjava/java/lang/Double.java | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/libjava/java/lang/Double.java b/libjava/java/lang/Double.java index caaa406..63ee265 100644 --- a/libjava/java/lang/Double.java +++ b/libjava/java/lang/Double.java @@ -146,6 +146,14 @@ public final class Double extends Number implements Comparable * <code>instanceof</code> <code>Double</code>, and represents * the same primitive <code>double</code> value return * <code>true</code>. Otherwise <code>false</code> is returned. + * <p> + * Note that there are two differences between <code>==</code> and + * <code>equals()</code>. <code>0.0d == -0.0d</code> returns <code>true</code> + * but <code>new Double(0.0d).equals(new Double(-0.0d))</code> returns + * <code>false</code>. And <code>Double.NaN == Double.NaN</code> returns + * <code>false</code>, but + * <code>new Double(Double.NaN).equals(new Double(Double.NaN))</code> returns + * <code>true</code>. * * @param obj the object to compare to * @return whether the objects are semantically equal. @@ -248,11 +256,9 @@ public final class Double extends Number implements Comparable */ public static boolean isNaN (double v) { - long bits = doubleToLongBits (v); - long e = bits & 0x7ff0000000000000L; - long f = bits & 0x000fffffffffffffL; - - return e == 0x7ff0000000000000L && f != 0L; + // This works since NaN != NaN is the only reflexive inequality + // comparison which returns true. + return v != v; } /** @@ -277,10 +283,7 @@ public final class Double extends Number implements Comparable */ public static boolean isInfinite (double v) { - long bits = doubleToLongBits (v); - long f = bits & 0x7fffffffffffffffL; - - return f == 0x7ff0000000000000L; + return (v == POSITIVE_INFINITY || v == NEGATIVE_INFINITY); } /** @@ -508,5 +511,5 @@ public final class Double extends Number implements Comparable * Initialize JNI cache. This method is called only by the * static initializer when using JNI. */ - private static void initIDs () { /* Not used in libgcj */ }; + private static native void initIDs (); } |