RFR: 8292301: [REDO v2] C2 crash when allocating array of size too large [v4]

[Roland Westrelin]

On Mon, 19 Sep 2022 22:08:48 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

>> Roland Westrelin has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 12 commits:
>> 
>>  - comments
>>  - Merge branch 'master' into JDK-8292301
>>  - Update src/hotspot/share/opto/phaseX.cpp
>>    
>>    Co-authored-by: Tobias Hartmann <tobias.hartmann at oracle.com>
>>  - undo needless change
>>  - dos->unix test file
>>  - move tests
>>  - test fix
>>  - fix
>>  - test
>>  - test for 8288184
>>  - ... and 2 more: https://git.openjdk.org/jdk/compare/8e22f2bb...9d92011a
>
> src/hotspot/share/opto/compile.cpp line 4034:
> 
>> 4032:         assert(call->is_CallStaticJava(), "static call expected");
>> 4033:         assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
>> 4034:         call->del_req(call->req()-1); // valid length test useless now
> 
> How you remove graph (test) attached to ValidLengthTest input? How you know that `call` node still has this input and it is `call->req() -1`?

You're right that the subgraph at ValidLengthTest goes dead and is not properly removed. I pushed a new change to fix that.
The ValidLengthTest input from the AllocateArrayNode is always moved to the call so there's no reason it shouldn't still be there.

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PR: https://git.openjdk.org/jdk/pull/10038