Changes scala.math.signum to return negative zeros.

2 files changed, 9 insertions, 14 deletions

diff --git a/src/library/scala/math/package.scala b/src/library/scala/math/package.scala
index 0417461f85..71a7f8e5ed 100644
--- a/src/library/scala/math/package.scala
+++ b/src/library/scala/math/package.scala
@@ -115,21 +115,10 @@ package object math {
   def min(x: Float, y: Float): Float  = java.lang.Math.min(x, y)
   def min(x: Double, y: Double): Double = java.lang.Math.min(x, y)
 
-  def signum(x: Double): Double =
-    if (x == 0d) 0d
-    else if (x < 0) -1.0
-    else if (x > 0) 1.0
-    else x    // NaN
-
-  def signum(x: Float): Float =
-    if (x == 0f) 0f
-    else if (x < 0) -1.0f
-    else if (x > 0) 1.0f
-    else x    // NaN
-
-  def signum(x: Long): Long = java.lang.Long.signum(x)
-
   def signum(x: Int): Int = java.lang.Integer.signum(x)
+  def signum(x: Long): Long = java.lang.Long.signum(x)
+  def signum(x: Float): Float = java.lang.Math.signum(x)
+  def signum(x: Double): Double = java.lang.Math.signum(x)
 
   // -----------------------------------------------------------------------
   // root functions
diff --git a/test/files/jvm/signum.scala b/test/files/jvm/signum.scala
index feb28d3e43..76602a6641 100644
--- a/test/files/jvm/signum.scala
+++ b/test/files/jvm/signum.scala
@@ -11,5 +11,11 @@ object Test {
     assert(math.signum(0) == 0)
     assert(math.signum(-1) == -1)
     assert(math.signum(Int.MinValue) == -1)
+
+    assert(java.lang.Float.floatToIntBits(math.signum(0f)) == 0x0)
+    assert(java.lang.Float.floatToIntBits(math.signum(-0f)) == 0x80000000)
+
+    assert(java.lang.Double.doubleToLongBits(math.signum(0d)) == 0x0L)
+    assert(java.lang.Double.doubleToLongBits(math.signum(-0d)) == 0x8000000000000000L)
   }
 }