RFR: 8328528: C2 should optimize long-typed parallel iv in an int counted loop [v17]

[Roland Westrelin]

On Fri, 27 Sep 2024 11:55:02 GMT, Roland Westrelin <roland at openjdk.org> wrote:

>> Kangcheng Xu has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   fix wrong expect values in test
>
> test/hotspot/jtreg/compiler/loopopts/parallel_iv/TestParallelIvInIntCountedLoop.java line 349:
> 
>> 347:             int init1 = rng.nextInt();
>> 348:             int init2 = rng.nextInt(Integer.MIN_VALUE + i + 1, i);
>> 349:             long init1L = rng.nextLong(Long.MIN_VALUE + i + 1, i);
> 
> I understand the init2 computation I think (i - init2 should not overflow max signed int value) but I don't understand the `init1L` one. As far as I can tell, `init1L` is used the same way `init1` is used but one is for a test with a long variable and the other for a int variable. Why don't they use the same initialization pattern then?

Can you add a comment as well?

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

PR Review Comment: https://git.openjdk.org/jdk/pull/18489#discussion_r1778534073