RFR: 8320448: Accelerate IndexOf using AVX2 [v48]

[Scott Gibbons]

On Thu, 30 May 2024 06:22:17 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> test/jdk/java/lang/StringBuffer/ECoreIndexOf.java line 29:
>> 
>>> 27:  * @requires vm.cpu.features ~= ".*avx2.*"
>>> 28:  * @requires vm.compiler2.enabled
>>> 29:  * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+EnableX86ECoreOpts -XX:UseAVX=2 -Xbatch -XX:-TieredCompilation -XX:CompileCommand=dontinline,ECoreIndexOf.indexOfKernel ECoreIndexOf
>> 
>> Does this test really need to be `avx2` specific? Does it even need to be C2 specific?
>> Or can this run on all platforms?
>
> Would be a shame to spend so much time on writing a test and then not apply it everywhere ;)

I'll add a separate @test block to this file.  It was, however, written specifically tuned for the new algorithm to exercise known edge cases.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/16753#discussion_r1620676513