RFR: 8331194: NPE in ArrayCreationTree.java with -XX:-UseCompressedOops [v2]

[Cesar Soares Lucas]

On Wed, 10 Jul 2024 09:44:08 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> Cesar Soares Lucas has updated the pull request incrementally with two additional commits since the last revision:
>> 
>>  - Update src/hotspot/share/opto/output.cpp
>>    
>>    Co-authored-by: Emanuel Peter <emanuel.peter at oracle.com>
>>  - Update src/hotspot/share/opto/machnode.hpp
>>    
>>    Co-authored-by: Emanuel Peter <emanuel.peter at oracle.com>
>
> test/hotspot/jtreg/compiler/c2/TestReduceAllocationAndNestedScalarized.java line 41:
> 
>> 39:  *                   -Xcomp
>> 40:  *                   -server
>> 41:  *                   compiler.c2.TestReduceAllocationAndNestedScalarized
> 
> Drive by comment: are all these `requires` absolutely necessary? Could there be a run without them? Is the test expected to fail with graal or C1? Or any external flags?
> 
> Could we have a run without some of the flags you list here? Just so that we have wider coverage, especially in combination with other flags that can be passed from the outside.

This test is intended to "test" a transformation in C2, it won't fail if run in C1, but it won't actually test what's intended for. The `flagless` option is to make sure that C2 produce an IR graph that will trigger the optimization, same reasoning for all the "CompileCommand" options. I may remove the "vm.bits" part, I included it because of the "-UseCompressedOops".

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PR Review Comment: https://git.openjdk.org/jdk/pull/20087#discussion_r1672620314