> 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 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 ten additional commits since the last revision: - Separate neon and sve functions into two source files - Merge branch 'jdk:master' into JDK-8312425 - Rename vmath to sleef in configure - Address review comments in build system - Add a bundled native lib in jdk as a bridge to libsleef - Merge 'jdk:master' into JDK-8312425 - Disable sleef by default - Merge 'jdk:master' into JDK-8312425 - 8312425: [vectorapi] AArch64: Optimize vector math operations with SLEEF ------------- Changes: - all: https://git.openjdk.org/jdk/pull/16234/files - new: https://git.openjdk.org/jdk/pull/16234/files/c1ce1968..ee5caf6d Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=16234&range=05 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16234&range=04-05 Stats: 638331 lines in 1866 files changed: 100400 ins; 474467 del; 63464 mod Patch: https://git.openjdk.org/jdk/pull/16234.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/16234/head:pull/16234 PR: https://git.openjdk.org/jdk/pull/16234
