Foreign + Vectors - benchmarks for copying and swapping

[Paul Sandoz]

Replacing the upper bound in `segmentImplicitScalar` with a constant (1024 say) results in a similar time to `bufferNativeScalar` without a constant bound, both of which (alas) are still slower that scalar array access (which benefits greatly from auto-vectorization).

I wonder if the segment subrange checking for int value ranges is having an impact on bounds checking?

Paul.

> On Jun 21, 2021, at 1:56 PM, Maurizio Cimadamore <maurizio.cimadamore at oracle.com> wrote:
> 
> 
> On 21/06/2021 20:33, Paul Sandoz wrote:
>> - Segment scalar access is penalized compared to ByteBuffer (from allocate or allocateDirect) scalar access.
> 
> Odd
> 
> We have many benchmarks similar to this (see LoopOverNonConstant) and they seem to offer same level of performance compared with ByteBuffers.
> 
> I wonder if the loop limit being "SPECIES.loopBound(srcArray.length)" plays a role? Have you tried replacing that expression with a constant?
> 
> Maurizio
>