RFR: 8364184: [REDO] AArch64: [VectorAPI] sve vector math operations are not supported after JDK-8353217

[Magnus Ihse Bursie]

On Thu, 31 Jul 2025 16:14:35 GMT, Fei Gao <fgao at openjdk.org> wrote:

> This patch fixes a typo introduced in JDK-8353217, which incorrectly disabled SVE vector math symbols. As a result, some vector math test cases such as `jdk/incubator/vector/Double256VectorTests.java` threw
> exceptions on 256-bit `sve` machines with errors like:
> `java.lang.InternalError: not supported: ACOS Species[double, 4, S_256_BIT] acosdx_u10sve.`
> 
> `test/jdk/jdk/incubator/vector` passed on 256-bit `sve` and `neon` machine.

Looks good, thanks for sorting this out! Note that this is dependent on https://github.com/openjdk/jdk/pull/26755.

make/autoconf/flags-cflags.m4 line 943:

> 941:   # libvectormath. Apple Silicon does not support SVE; use macOS as a proxy for
> 942:   # that check.
> 943:   if test "x$OPENJDK_TARGET_CPU" = "xaarch64" && test "x$OPENJDK_TARGET_CPU" = "xlinux"; then

This is really disturbing! Has really no-one noticed until now that SVE support broke with 8353217?

Also, this PR fixes two unrelated errors -- a bug introduced in JDK-8353217, and a compiler error. I think it would be better for everybody's sanity, and future backport efforts, if you split it into two.

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PR Comment: https://git.openjdk.org/jdk/pull/26577#issuecomment-3187817040
PR Review Comment: https://git.openjdk.org/jdk/pull/26577#discussion_r2266095631