[aarch64-port-dev ] RFR: 8081289: aarch64: add support for RewriteFrequentPairs in interpreter

[Edward Nevill]

Hi,

The following webrev adds support for RewriteFrequentPairs to the template interpreter for aarch64.

http://cr.openjdk.java.net/~enevill/8081289/webrev.00

This was contributed by Alexander Alexeev (alexander.alexeev at caviumnetworks.com)

This gives a small improvement to the interpreter on aarch64, and brings it in line with all the other ports (x86, sparc, ppc, zero) which all support RewriteFrequentPairs.

I have done some performance measurement using -Xint with some micro benchmarks and I see a small improvement on each.

java dhrystone: +9%
embedded caffeinemark: +4%
grinderbench: +1%
dacapo (avrora): +1%

Tested with hotspot jtreg:-

Original: Test results: passed: 787; failed: 24; error: 44
With patch: Test results: passed: 785; failed: 24; error: 46

The difference in the # of errors is due to timeouts because we are running -Xint.

Please review and if OK I will push.

All the best,
Ed.