On Tue, 15 Jun 2021 12:15:11 GMT, Сергей Цыпанов <d...@openjdk.java.net> wrote:
> In some JDK classes there's still the following hashCode() implementation: > > long objNum; > > public int hashCode() { > return (int) objNum; > } > > This outdated expression should be replaced with Long.hashCode(long) as it > > - uses all bits of the original value, does not discard any information > upfront. For example, depending on how you are generating the IDs, the upper > bits could change more frequently (or the opposite). > > - does not introduce any bias towards values with more ones (zeros), as it > would be the case if the two halves were combined with an OR (AND) operation. > > See https://stackoverflow.com/a/4045083 > > This is related to https://github.com/openjdk/jdk/pull/4309 This pull request has now been integrated. Changeset: 124f8237 Author: Sergey Tsypanov <sergei.tsypa...@yandex.ru> Committer: Sergey Bylokhov <s...@openjdk.org> URL: https://git.openjdk.java.net/jdk/commit/124f82377ba93359bc59118ee315ba194080fa92 Stats: 21 lines in 9 files changed: 6 ins; 0 del; 15 mod 8268764: Use Long.hashCode() instead of int-cast where applicable Reviewed-by: kevinw, prr, kizune, serb ------------- PR: https://git.openjdk.java.net/jdk/pull/4491