On Wed, 28 May 2025 18:36:38 GMT, Mohamed Issa <d...@openjdk.org> wrote:
>> 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 four additional > commits since the last revision: > > - Remove comment mentioning invalid exception when NaN input is provided > - Use rcx as base and r8 as index for address calculations in certain cbrt > stub generator instructions > - Remove unnecessary unpckhpd and unpcklpd definitions in macro-assembler > header file > - Remove unnecessary movapd definitions in macro-assembler header file Looks good to me. ------------- Marked as reviewed by sviswanathan (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/24470#pullrequestreview-2876071455
