On Fri, 11 Apr 2025 21:23:52 GMT, Vladimir Ivanov <vliva...@openjdk.org> wrote:
>> Migrate Vector API math library (SVML and SLEEF) linkage from native code >> (in JVM) to Java FFM API. >> >> Since FFM API doesn't support vector calling conventions yet, migration >> affects only symbol lookup for now. But it still enables significant >> simplifications on JVM side. >> >> The patch consists of the following parts: >> * on-demand symbol lookup in Java code replaces eager lookup from native >> code during JVM startup; >> * 2 new VM intrinsics for vector calls (support unary and binary shapes) >> (code separated from unary/binary vector operations); >> * new internal interface to query supported CPU ISA extensions >> (`jdk.incubator.vector.CPUFeatures`) used for CPU dispatching. >> >> `java.lang.foreign` API is used to perform symbol lookup in vector math >> library, then the address is cached and fed into corresponding JVM >> intrinsic, so C2 can turn it into a direct vector call in generated code. >> >> Once `java.lang.foreign` supports vectors & vector calling conventions, VM >> intrinsics can go away. >> >> Performance is on par with original implementation (tested with >> microbenchmarks on linux-x64 and macosx-aarch64). >> >> Testing: hs-tier1 - hs-tier6, microbenchmarks (on linux-x64 and >> macosx-aarch64) >> >> Thanks! > > Vladimir Ivanov 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 19 additional > commits since the last revision: > > - Merge branch 'master' into vector.math.01.java > - RVV and SVE adjustments > - Merge branch 'master' into vector.math.01.java > - Fix windows-aarch64 build failure > - features_string -> cpu_info_string > - Reviews and Float64Vector-related fix > - Misc fixes and cleanups > - CPU features support > - Cleanup > - TODO list > - ... and 9 more: https://git.openjdk.org/jdk/compare/d3c46607...0ffed12f src/jdk.incubator.vector/share/classes/jdk/incubator/vector/VectorMathLibrary.java line 240: > 238: if (isAARCH64() && vspecies.vectorBitSize() > 128) { > 239: return false; // FIXME: SVE support only for MAX > shapes > 240: } SVE also supports operations for partial vector size, which means the vector size is smaller than MAX size. For example, if the max vector size of a SVE architecture is 512-bit, the FP vector operations with `VectorShape.S_256_BIT` are also supported. They are implemented with the same scalable math functions in SLEEF. Hence, I think this check and the assertion in line-198 can be removed. Thanks! ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/24462#discussion_r2045871389
