RFR: 8331558: AArch64: optimize integer remainder [v3]

[Jin Guojie]

> 8331558: AArch64: optimize integer remainder
>     On some Arm processors, a separate multiply/subtract is actually faster than the combined instruction.
> 
> 8331556: AArch64: CPU_Model support for Neoverse N1/N2/V1/V2
>     Add full platform coverage for Neoverse variants in vm_version.?pp
> 
> The following test has passed, which shows definite performance improvement.
> 
> make test TEST="micro:java.lang.IntegerDivMod"
> make test TEST="micro:java.lang.LongDivMod"
> 
> * IntegerDivMod.testDivideRemainderUnsigned
> baseline(ns/ops)                2223
> with this pacth(ns/ops)         1885    
> improvement(%)                  17.93%
> 
> * IntegerDivMod.testRemainderUnsigned
> baseline(ns/ops)                2225
> with this pacth(ns/ops)         1885    
> improvement(%)                  18.03%
> 
> * LongDivMod.testDivideRemainderUnsigned
> baseline(ns/ops)                2231
> with this pacth(ns/ops)         1894    
> improvement(%)                  17.79%
> 
> * LongDivMod.testRemainderUnsigned
> baseline(ns/ops)                2232
> with this pacth(ns/ops)         1891
> improvement(%)                  18.03%

Jin Guojie has updated the pull request incrementally with one additional commit since the last revision:

  Applicable platforms expanded to the entire neoverse family
  
  Even on the V series (V1 and V2), both sdiv/udiv and msub instructions are executed in M0 unit (Integer multi cycle). It should benefit the V series as well.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/19093/files
  - new: https://git.openjdk.org/jdk/pull/19093/files/786d5016..d8b8dbfe

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=19093&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=19093&range=01-02

  Stats: 6 lines in 1 file changed: 0 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/19093.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19093/head:pull/19093

PR: https://git.openjdk.org/jdk/pull/19093