RFR: 8345485: C2 MergeLoads: merge adjacent array/native memory loads into larger load [v4]

[kuaiwei]

On Tue, 18 Mar 2025 08:27:44 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> kuaiwei has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Revert extract value and add more tests
>
> test/hotspot/jtreg/compiler/c2/TestMergeLoads.java line 290:
> 
>> 288:       int[] ret = {i1};
>> 289:       return new Object[]{ret};
>> 290:     }
> 
> Ah, I see you are using `|`. Can we also use `+`?
> 
> FYI: if you use `Verify.java`, then you could directly do `return i2;`. It would get returned as a boxed `Integer`, and should be compared that way, without allocating an `int[]` and `Object[]`.

Now I only check ‘|’, so they can not be merged if using '+'. But I think it can be extended.

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PR Review Comment: https://git.openjdk.org/jdk/pull/24023#discussion_r2000530238