RFR: 8309129: AArch64: guarantee(T != T2S) failed: "incorrect arrangement" after JDK-8307795

[Evgeny Astigeevich]

On Wed, 31 May 2023 10:25:07 GMT, Chang Peng <duke at openjdk.org> wrote:

> This patch fixes the issue introduced by JDK-8307795. Since addv[1] cannot support "T2S" SIMD arrangement, we should use addp[2] in this case.
> 
> TEST passed on AArch64:
> hotspot:compiler/vectorapi, jdk:jdk/incubator/vector, tier1-3
> 
> [1]: https://developer.arm.com/documentation/ddi0596/2020-12/SIMD-FP-Instructions/ADDV--Add-across-Vector-
> [2]: https://developer.arm.com/documentation/ddi0596/2020-12/SIMD-FP-Instructions/ADDP--vector---Add-Pairwise--vector--

src/hotspot/cpu/aarch64/aarch64_vector.ad line 5528:

> 5526:     Assembler::SIMD_Arrangement arrangement = Assembler::esize2arrangement(esize,
> 5527:                                                                            /* isQ */ length_in_bytes == 16);
> 5528:     if (arrangement == __ T2D || arrangement == __ T2S) {

I see `jdk/incubator/vector/Float64VectorTests.java` covers the case `arrangement == __ T2S`.
Is there a test covering the case `arrangement == __ T2D`?

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PR Review Comment: https://git.openjdk.org/jdk/pull/14245#discussion_r1211596675