> The goal of this PR is to implement an x86_64 intrinsic for > java.lang.Math.cbrt() using libm. There is a new set of micro-benchmarks are > included to check the performance of specific input value ranges to help > prevent regressions in the future. > > The command to run all range specific micro-benchmarks is posted below. > > `make test TEST="micro:CbrtPerf.CbrtPerfRanges"` > > The results of all tests posted below were captured with an [Intel® Xeon > 6761P](https://www.intel.com/content/www/us/en/products/sku/241842/intel-xeon-6761p-processor-336m-cache-2-50-ghz/specifications.html) > using [OpenJDK > v25-b21](https://github.com/openjdk/jdk/releases/tag/jdk-25%2B21) as the > baseline version. > > For performance data collected with the new built in range micro-benchmark, > see the table below. Each result is the mean of 8 individual runs, and the > input ranges used match those from the original Java implementation. Overall, > the intrinsic provides a major uplift of 169% when very small inputs are used > and a more modest uplift of 45% for all other inputs. > > | Input range(s) | Baseline throughput > (ops/ms) | Intrinsic throughput (ops/ms) | Speedup | > | :-------------------------------------: | :-------------------------------: > | :-------------------------------: | :---------: | > | [-2^(-1022), 2^(-1022)] | 6568 > | 17678 | 2.69x | > | (-INF, -2^(-1022)], [2^(-1022), INF) | 138932 > | 200897 | 1.45x | > > Finally, the `jtreg:test/jdk/java/lang/Math/CubeRootTests.java` test passed > with the changes.
Mohamed Issa has updated the pull request incrementally with two additional commits since the last revision: - Add newline back to templateInterpreterGenerator_x86_64.cpp source file - Add special case values to cbrt micro-benchmark set ------------- Changes: - all: https://git.openjdk.org/jdk/pull/24470/files - new: https://git.openjdk.org/jdk/pull/24470/files/ff4d4f22..233e0188 Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=24470&range=04 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24470&range=03-04 Stats: 40 lines in 2 files changed: 39 ins; 0 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/24470.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/24470/head:pull/24470 PR: https://git.openjdk.org/jdk/pull/24470
