RFR: AARCH64: optimize string compare intrinsic

[Dmitrij Pochepko]

On 04.05.2018 16:46, Andrew Haley wrote:
> On 05/04/2018 02:24 PM, Dmitrij Pochepko wrote:
>> Do you suggest to change vectorizedMismatch from generic single entry
>> point to 4 versions (1,2,4 and 8 -byte) each optimized for respective
>> size(and possible re-using code generation logic)? Then it can be
>> re-used for same-encoded strings without penalties, indeed, but it
>> requires changes in jdk.internal.util.ArraysSupport.java
> I don't see why it's absolutely necessary.  On the other hand, it might
> be an excellent idea to have a switch statement in the Java code wich
> will almost always optimized away.  It's worth trying.
>
As this is a separate possibly multiplatform effort which potentially 
affects common code and x86 platform intrinsic implementation I created 
a separate enhancement for this issue: 
https://bugs.openjdk.java.net/browse/JDK-8202783

Let me know if you have any comments on the patch.

Thanks,
Dmitrij