Reply: Aarch64: optimation for doing remainder on AArch64

[Jin Guojie]

Hi Andrew,

These days we used the microbenchmark that comes with JDK to conduct a more comprehensive performance test on this remainder optimization.

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%

There is also good news. My OCA application has been approved.

Could you please create an issue in the JDK Bug System (JBS) before I submit a PR? Thanks.

Jin Guojie (Alibaba, hotspot developer).

On 2024/4/ 23:42 Andrew Haley <aph-open at littlepinkcloud.com> wrote:

>> If you can get a Github account and an OpenJDK account we can start to do that.
>> The first thing for you to do is clone the OpenJDK repo into your own tree,
>> then create a local branch, then create a PR.

>> See the section https://openjdk.org/guide/#i-have-a-patch-what-do-i-do

> According to this guide, a sponsor needs to first create an issue on JBS before submitting a PR.
> Could you please create an issue in the JDK Bug System (JBS)?
> I have submitted an OpenJDK account application, but But Oracle has not approved it yet.
> I will submit this PR after my OCA is signed and the the issure in JBS is created.