RFR: 8327963: C2: fix construction of memory graph around Initialize node to prevent incorrect execution if allocation is removed [v15]

[Roland Westrelin]

On Fri, 24 Oct 2025 13:31:16 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> Roland Westrelin has updated the pull request incrementally with two additional commits since the last revision:
>> 
>>  - review
>>  - Roberto's patches
>
> src/hotspot/share/opto/multnode.cpp line 273:
> 
>> 271:   ProjNode::dump_compact_spec(st);
>> 272:   MemNode::dump_adr_type(_adr_type, st);
>> 273: }
> 
> Can you show us an example out put of `dump`? I'm just wondering if there maybe needs to be a space between the two, and if it is immediately readable :)

Actually, `Node::dump` already takes care of dumping the `adr_type`. So I removed the `dump` methods from `NarrowMemProjNode`. Here is an example output:


 59  Initialize  === 83 1 62 1 1 1 121  [[ 124 123 63 64 65 ]]  !jvms: TestInitializingStoreCapturing::testInitializeArray @ bci:1 (line 57)                                                                                                                                     
TestInitializingStoreCapturing::testInitializeArray @ bci:1 (line 57)                                    
  63  NarrowMemProj  === 59  [[ 15 ]] #2  Memory: @java/lang/Object *, idx=4; !jvms: TestInitializingStoreCapturing::testInitializeArray @ bci:1 (line 57)                                                                                                                        
  64  NarrowMemProj  === 59  [[ 15 ]] #2  Memory: @java/lang/Object+8 * [narrowklass], idx=5; !jvms: TestInitializingStoreCapturing::testInitializeArray @ bci:1 (line 57)                                                                                                        
  65  NarrowMemProj  === 59  [[ 15 ]] #2  Memory: @float[int:>=0] (java/lang/Cloneable,java/io/Serializable):exact+any *, idx=6; !jvms: TestInitializingStoreCapturing::testInitializeArray @ bci:1 (line 57)                                                                     
  66  CheckCastPP  === 125 86  [[ 79 ]]  #float[int:1] (java/lang/Cloneable,java/io/Serializable):NotNull:exact * !jvms: TestInitializingStoreCapturing::testInitializeArray @ bci:1 (line 57)

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

PR Review Comment: https://git.openjdk.org/jdk/pull/24570#discussion_r2469429116