RFR: 8321279: Implement hashCode() in Heap-X-Buffer.java.template [v7]

[Sergey Tsypanov]

On Tue, 12 Dec 2023 08:01:47 GMT, Sergey Tsypanov <stsypanov at openjdk.org> wrote:

>> Currently `Heap*Buffer.hashCode()` is inherited from `*Buffer` and implemented as 
>> 
>> public int hashCode() {
>>     int h = 1;
>>     int p = position();
>>     for (int i = limit() - 1; i >= p; i--)
>>         h = 31 * h + (int)get(i);
>>     return h;
>> }
>> 
>> This can be improved using `ArraysSupport.vectorizedHashCode()`
>
> Sergey Tsypanov has updated the pull request incrementally with one additional commit since the last revision:
> 
>   8320971: Rename method

I've run the tests again on VM, no significant difference

master

Benchmark                     (size)  Mode  Cnt      Score      Error  Units
ByteBuffers.testHeapHashCode      16  avgt   30      9.956 ?    0.537  ns/op
ByteBuffers.testHeapHashCode    1024  avgt   30    639.355 ?    4.158  ns/op
ByteBuffers.testHeapHashCode  131072  avgt   30  84327.624 ? 1231.085  ns/op

patch

Benchmark                     (size)  Mode  Cnt      Score      Error  Units
ByteBuffers.testHeapHashCode      16  avgt   30      7.791 ?    0.158  ns/op
ByteBuffers.testHeapHashCode    1024  avgt   30    669.107 ?   10.464  ns/op
ByteBuffers.testHeapHashCode  131072  avgt   30  85484.992 ? 2064.665  ns/op

I think in a week I'll be able to run this on Linux machine

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PR Comment: https://git.openjdk.org/jdk/pull/16992#issuecomment-1851829328