Bring Statics.doubleHash in sync with BoxesRunTime.hashFromDouble.

The two algorithms were different, and could result in different
hash codes for some values, namely, valid long values that were
not also valid int values.

The other two functions `longHash` and `floatHash` are rewritten
to keep a common style with `doubleHash`, but their algorithm
does not change.

1 files changed, 8 insertions, 0 deletions

diff --git a/test/junit/scala/runtime/ScalaRunTimeTest.scala b/test/junit/scala/runtime/ScalaRunTimeTest.scala
index 5bfb12610e..9efbdd44de 100644
--- a/test/junit/scala/runtime/ScalaRunTimeTest.scala
+++ b/test/junit/scala/runtime/ScalaRunTimeTest.scala
@@ -9,6 +9,14 @@ import org.junit.runners.JUnit4
 @RunWith(classOf[JUnit4])
 class ScalaRunTimeTest {
   @Test
+  def hashConsistentWithStaticsHash(): Unit = {
+    val problematicValue: Double = -Math.pow(2, 53) + 1
+    val scalaRunTimeHash = ScalaRunTime.hash(problematicValue)
+    val staticsHash = Statics.anyHash(problematicValue)
+    assertEquals(scalaRunTimeHash, staticsHash)
+  }
+
+  @Test
   def testStingOf() {
     import ScalaRunTime.stringOf
     import scala.collection._