RFR: 8375653: C2: CmpUNode::sub is not monotonic [v5]

[Quan Anh Mai]

On Fri, 23 Jan 2026 07:40:52 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

>> Quan Anh Mai has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Improve IR tests
>
> test/hotspot/jtreg/compiler/ccp/TestCmpUMonotonicity.java line 35:
> 
>> 33: public class TestCmpUMonotonicity {
>> 34:     public static void main(String[] args) {
>> 35:         for (int i = 0; i < 20000; i++) {
> 
> But do you really need 20000 iterations to trigger the issue? We end up executing the inner loop 20000*50 times. But it's not much work in the loop, so probably does not matter too much.

Thanks for your approval, the inner loop update statement is `i *= step` instead of `i += step`, so the inner loop runs only 7 iterations.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/29308#discussion_r2720143519