On Wed, 9 Aug 2023 22:54:28 GMT, Pavel Rappo <pra...@openjdk.org> wrote:
>> Please review this PR to use modern APIs and language features to simplify >> equals, hashCode, and compareTo for BigInteger. If you have any performance >> concerns, please raise them. >> >> This PR is cherry-picked from a bigger, not-yet-published PR, to test the >> waters. That latter PR will be published soon. > > Pavel Rappo has updated the pull request with a new target base due to a > merge or a rebase. The incremental webrev excludes the unrelated changes > brought in by the merge/rebase. The pull request contains 13 additional > commits since the last revision: > > - Fix bugs in Shared.createSingle > - Merge branch 'master' into 8310813 > - Group params coarser (suggested by @cl4es) > > - Splits 20 params into 3 groups: (S)mall, (M)edium and (L)arge. > Every testXYZ method invokes M operations, where M is the maximum > number of elements in a group. Shorter groups are cyclically padded. > - Uses the org.openjdk.jmh.infra.Blackhole API and increases > benchmark time. > - Fixes a bug in Shared that precluded 0 from being in a pair. > - Use better overloads (suggested by @cl4es) > > - Uses simpler, more suitable overloads for the subrange > starting from 0 > - Improve benchmarks > - Merge branch 'master' into 8310813 > - Restore hash code values > > BigInteger is old and ubiquitous enough so that there might be > inadvertent dependencies on its hash code. > > This commit also includes a test, to make sure hash code is > unchanged. > - Merge branch 'master' into 8310813 > - Add a benchmark > - Merge branch 'master' into 8310813 > - ... and 3 more: https://git.openjdk.org/jdk/compare/d5d285cb...6fa3f694 This looks good, thanks for the microbenchmark updates. Your work on this PR was what prompted me to look at `ArraysSupport.mismatch` performance. The patch in #15197 should mitigate at least some of the overhead we've seen on small `BigInteger` objects on `equals` and `compareTo` micros test/micro/org/openjdk/bench/java/math/Shared.java line 82: > 80: } > 81: int nBytes = (nBits + 7) / 8; > 82: var r = new Random(); Some have a preference for providing a seed for `Random` instances in micros. Either hard-coded or through a `@Param` (I find this a bit excessive). Doing so might reduce run-to-run noise. ------------- Marked as reviewed by redestad (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/14630#pullrequestreview-1570712845 PR Review Comment: https://git.openjdk.org/jdk/pull/14630#discussion_r1289313113
