RFR(M) 8188165: PPC64: Optimize Unsafe.copyMemory and arraycopy

Matthew Brandyberry mbrandy at linux.vnet.ibm.com
Thu Oct 12 16:16:16 UTC 2017


On 9/29/17 4:00 PM, Matthew Brandyberry wrote:
> This is specific to PPC64LE only.
> The emphasis in the proposed code is on minimizing branches. Thus, 
> this code makes no attempt to avoid misaligned accesses and each block 
> is designed to copy as many elements as possible.
> As one data point, this yields as much as a 13x improvement in 
> jbyte_disjoint_arraycopy for certain misaligned scenarios.
> Bug: https://bugs.openjdk.java.net/browse/JDK-8188165
> Webrev: http://cr.openjdk.java.net/~mbrandy/8188165/jdk10/v1/
> Thanks,
> -Matt

More information about the hotspot-dev mailing list