RFR: 8323220: Reassociate loop invariants involved in Cmps and Add/Subs [v10]

[Joshua Cao]

On Fri, 16 Feb 2024 07:29:16 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> Joshua Cao has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 12 additional commits since the last revision:
>> 
>>  - Update test to utilize @setup method for arguments
>>  - Merge branch 'master' into licm
>>  - Add correctness test for some random tests with random inputs
>>  - Add some correctness tests where we do reassociate
>>  - Remove unused TestInfo parameter. Have some tests exit mid-loop.
>>  - Merge branch 'master' into licm
>>  - Small fixes and add check methods for tests
>>  - reassociate_add_sub -> reassociate_add_sub_cmp
>>  - Formatting and fix typo
>>  - Assert for n2. Variables for n1/n2 opcode. More concise comments.
>>    Overflow/random tests
>>  - ... and 2 more: https://git.openjdk.org/jdk/compare/c715eb59...ad073ef2
>
> test/hotspot/jtreg/compiler/loopopts/InvariantCodeMotionReassociateCmp.java line 66:
> 
>> 64:             }
>> 65:             // Setup inputs to be equals sometimes to avoid uncommon traps
>> 66:             inv2 = inv1;
> 
> You may want to use the `SetupInfo` instead, and make this deterministic. Just in the case where the randomness here fails in all cases - then you would not have any equal case.
> Also: why can `inv1` not be zero?

Sure, can look into `SetupInfo`.

`inv1` can be zero. I'll remove that block.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/17375#discussion_r1492140006