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

[Vladimir Sitnikov]

On Wed, 6 Dec 2023 13:31:02 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()`

src/java.base/share/classes/java/nio/Heap-X-Buffer.java.template line 710:

> 708: 
> 709:     public int hashCode() {
> 710:         return ArraysSupport.vectorizedHashCode(hb, position(), limit() - position(), 1, ArraysSupport.T_BYTE);

Suggestion:

        return ArraysSupport.vectorizedHashCode(hb, ix(offset()), remaining(), 1, ArraysSupport.T_BYTE);

src/java.base/share/classes/java/nio/Heap-X-Buffer.java.template line 741:

> 739: 
> 740:     public int hashCode() {
> 741:         return ArraysSupport.vectorizedHashCode(hb, position(), limit() - position(), 1, ArraysSupport.T_CHAR);

Suggestion:

        return ArraysSupport.vectorizedHashCode(hb, ix(position()), remaining(), 1, ArraysSupport.T_CHAR);

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PR Review Comment: https://git.openjdk.org/jdk/pull/16992#discussion_r1417519895
PR Review Comment: https://git.openjdk.org/jdk/pull/16992#discussion_r1417521502