On Thu, 7 Dec 2023 09:30:01 GMT, Xiaohong Gong <xg...@openjdk.org> wrote:
>> Currently the vector floating-point math APIs like >> `VectorOperators.SIN/COS/TAN...` are not intrinsified on AArch64 platform, >> which causes large performance gap on AArch64. Note that those APIs are >> optimized by C2 compiler on X86 platforms by calling Intel's SVML code [1]. >> To close the gap, we would like to optimize these APIs for AArch64 by >> calling a third-party vector library called libsleef [2], which are >> available in mainstream Linux distros (e.g. [3] [4]). >> >> SLEEF supports multiple accuracies. To match Vector API's requirement and >> implement the math ops on AArch64, we 1) call 1.0 ULP accuracy with FMA >> instructions used stubs in libsleef for most of the operations by default, >> and 2) add the vector calling convention to apply with the runtime calls to >> stub code in libsleef. Note that for those APIs that libsleef does not >> support 1.0 ULP, we choose 0.5 ULP instead. >> >> To help loading the expected libsleef library, this patch also adds an >> experimental JVM option (i.e. `-XX:UseSleefLib`) for AArch64 platforms. >> People can use it to denote the libsleef path/name explicitly. By default, >> it points to the system installed library. If the library does not exist or >> the dynamic loading of it in runtime fails, the math vector ops will >> fall-back to use the default scalar version without error. But a warning is >> printed out if people specifies a nonexistent library explicitly. >> >> Note that this is a part of the original proposed patch in panama-dev [5], >> just with some initial review comments addressed. And now we'd like to get >> some wider feedbacks from more hotspot experts. >> >> [1] https://github.com/openjdk/jdk/pull/3638 >> [2] https://sleef.org/ >> [3] https://packages.fedoraproject.org/pkgs/sleef/sleef/ >> [4] https://packages.debian.org/bookworm/libsleef3 >> [5] https://mail.openjdk.org/pipermail/panama-dev/2022-December/018172.html > > Xiaohong Gong has updated the pull request incrementally with one additional > commit since the last revision: > > Fix potential attribute issue > Build changes finally look good. Great, actually! Thanks for persisting, > despite the many rounds of review. > > You will still need the 2 hotspot reviews for the hotspot part of the patch. > > /reviewers 3 Thanks for the review and all the comments! ------------- PR Comment: https://git.openjdk.org/jdk/pull/16234#issuecomment-1846330893
