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

[Roland Westrelin]

On Thu, 8 Sep 2022 07:16:26 GMT, Tobias Hartmann <thartmann at openjdk.org> wrote:

> Looks good otherwise.

Thanks for reviewing.

> src/hotspot/share/opto/loopopts.cpp line 2040:
> 
>> 2038:       // loop to determine which way the loop exited.
>> 2039:       // Loop predicate If node connects to Bool node through Opaque1 node.
>> 2040:       if (use->is_If() || use->is_CMove() || C->is_predicate_opaq(use) || use->Opcode() == Op_Opaque4 ||
> 
> Please add a comment describing the new case.

Done in updated change.

> src/hotspot/share/opto/loopopts.cpp line 2410:
> 
>> 2408:     while (split_if_set->size()) {
>> 2409:       Node *iff = split_if_set->pop();
>> 2410:       uint input = iff->Opcode() == Op_AllocateArray ? AllocateNode::ValidLengthTest : 1;
> 
> Suggestion:
> 
>       uint input = (iff->Opcode() == Op_AllocateArray) ? AllocateNode::ValidLengthTest : 1;

I left that one out as I think this pattern is common enough that it shouldn't be ambiguous.

> src/hotspot/share/opto/phaseX.cpp line 1643:
> 
>> 1641:       }
>> 1642:     }
>> 1643:     if (use_op == Op_AllocateArray && n == use->in(AllocateNode::ValidLengthTest)) {
> 
> Please add a comment.

Done in an updated change.

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