The goal of the PR is to improve both, sequential and parallel, sorting of primitives.
**The main achievements** - introduced Radix in parallel sorting which shows several times boost of performance and has linear complexity instead of n*ln(n) - improved mixed insertion sort (makes whole sorting faster) - improved merging sort for almost sorted data - optimized parallel sorting - improved step for pivot candidates and pivot partitioning - suggested better buffer allocation: if no memory, it is switched to in-place sorting with no OutOfMemoryError - minor javadoc and comment changes - extended existing tests - added tests for radix sort, heap sort, insertion sort - added benchmarking JMH tests - improved test coverage **The summary of benchmarking:** **Sequential sorting (Arrays.sort)** byte: up to 50% faster char: 4-7 times faster short: 2-6 times faster int: 1.2-5 times faster long: 1.2-5 times faster float: 1.2-5 times faster double: 1.2-4 times faster **Parallel sorting (Arrays.parallelSort)** int: 1.2-9 times faster long: 1.2-9 times faster float: 1.2-4 times faster double: 1.2-4 times faster **AVX512 support** Vamsi Parasa suggested faster sort routines by taking advantage of AVX512 instructions, see https://github.com/openjdk/jdk/pull/14227, sources of sorting were modified. Therefore, I performed benchmarking of the final version (which includes optimizations by Vamsi Parasa and optimizations from my side) on a server with CPUs supported AVX512 instructions, no regression of performance was found, see detailed benchmarking results. I'm going on previous PRs https://github.com/openjdk/jdk/pull/3938 and https://github.com/openjdk/jdk/pull/13568 ------------- Commit messages: - JDK-8266431: Dual-Pivot Quicksort improvements (Radix sort) - JDK-8266431: Dual-Pivot Quicksort improvements (Radix sort) Changes: https://git.openjdk.org/jdk/pull/27411/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27411&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8266431 Stats: 6295 lines in 4 files changed: 2359 ins; 1907 del; 2029 mod Patch: https://git.openjdk.org/jdk/pull/27411.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/27411/head:pull/27411 PR: https://git.openjdk.org/jdk/pull/27411
