RFR: 8294194: [AArch64] Create intrinsics compress and expand [v2]

[Stuart Monteith]

On Tue, 1 Nov 2022 08:45:50 GMT, Andrew Haley <aph at openjdk.org> wrote:

>> Stuart Monteith has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Update src/hotspot/cpu/aarch64/aarch64.ad
>>   
>>   Correct slight formatting error.
>>   
>>   Co-authored-by: Eric Liu <eric.c.liu at arm.com>
>
> src/hotspot/cpu/aarch64/aarch64.ad line 16958:
> 
>> 16956:     __ mov($tsrc$$FloatRegister, __ S, 0, $src$$Register);
>> 16957:     __ mov($tmask$$FloatRegister, __ S, 0, $mask$$Register);
>> 16958:     __ sve_bext($tdst$$FloatRegister, __ S, $tsrc$$FloatRegister, $tmask$$FloatRegister);
> 
> The long latency of core <-> vector moves will be hurting us here. Loading operands from memory directly into vectors might help, as might an immediate form of the mask.

I'll try this out - I imagine we could specialise this in the way you suggest.

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

PR: https://git.openjdk.org/jdk/pull/10537