On Mon, 7 Apr 2025 23:03:03 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 incrementally with one > additional commit since the last revision: > > features_string -> cpu_info_string In addition to addressing review feedback, there are 2 updates: * SVML: I overlooked that 64-bit vectors are covered by original implementation; fixed now; * JVM: `features_string` to `cpu_info_string` renaming uniformly across all platforms ------------- PR Comment: https://git.openjdk.org/jdk/pull/24462#issuecomment-2784850623
