RFR: 8263707: C1 RangeCheckEliminator support constant array and NewMultiArray

[Nils Eliasson]

On Tue, 23 Mar 2021 07:00:22 GMT, Tobias Hartmann <thartmann at openjdk.org> wrote:

>> …rray
>> 
>> C1 misses range check elimination opportunities for constant and NewMultiArray with fixed length now. This patch adds constant length node for load/store Indexed node when array is constant array or allocated with NewMultiArray  and its first dimension length is constant.
>> 
>> Tested on linux x64 release/fastdebug with tier1 and tier2.
>> 
>> Regards
>> Hui
>
> Looks good to me. I've also executed some internal testing and it all passed.

> > Do you have any test that exercises this code path?
> 
> @neliasso
> 
> I have an example case in JBS https://bugs.openjdk.java.net/secure/attachment/93668/range_check.java. Do you suggest adding a test case to check if RC is removed as expected?

Yes - please do that. Look at the tests in open/test/hotspot/jtreg/compiler/c1 (for example RangeCheckVerificationOfIR.java).

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

PR: https://git.openjdk.java.net/jdk/pull/3041