diff options
Diffstat (limited to 'src/library/scala/collection/mutable/FlatHashTable.scala')
| -rw-r--r-- | src/library/scala/collection/mutable/FlatHashTable.scala | 18 |
1 files changed, 4 insertions, 14 deletions
diff --git a/src/library/scala/collection/mutable/FlatHashTable.scala b/src/library/scala/collection/mutable/FlatHashTable.scala index 25cc873b82..8c4115b1dd 100644 --- a/src/library/scala/collection/mutable/FlatHashTable.scala +++ b/src/library/scala/collection/mutable/FlatHashTable.scala @@ -10,6 +10,9 @@ package scala package collection package mutable +import java.lang.Integer.rotateRight +import scala.util.hashing.byteswap32 + /** An implementation class backing a `HashSet`. * * This trait is used internally. It can be mixed in with various collections relying on @@ -415,20 +418,7 @@ private[collection] object FlatHashTable { // so that: protected final def sizeMapBucketSize = 1 << sizeMapBucketBitSize - protected final def improve(hcode: Int, seed: Int) = { - //var h: Int = hcode + ~(hcode << 9) - //h = h ^ (h >>> 14) - //h = h + (h << 4) - //h ^ (h >>> 10) - - val improved= scala.util.hashing.byteswap32(hcode) - - // for the remainder, see SI-5293 - // to ensure that different bits are used for different hash tables, we have to rotate based on the seed - val rotation = seed % 32 - val rotated = (improved >>> rotation) | (improved << (32 - rotation)) - rotated - } + protected final def improve(hcode: Int, seed: Int) = rotateRight(byteswap32(hcode), seed) /** * Elems have type A, but we store AnyRef in the table. Plus we need to deal with |