RFR: 8348261: assert(n->is_Mem()) failed: memory node required

[Vladimir Kozlov]

On Fri, 7 Mar 2025 00:44:44 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

> Add missing check for StrInflatedCopy intrinsic in C2 Escape Analysis.
> 
> Very rare case since we not usually use Latin1.inflate(). In failing case we inline both paths in [String.getBytes()](https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/lang/String.java#L4808) and eliminate `TreeMap$EntryIterator allocation:
> 
> 
>         # java.lang.String::getBytes @ bci:40 (line 4812) L[0]=rsp + #64 L[1]=rsp + #132 L[2]=rsp + #120 L[3]=rsp + #124 STK[0]=rsp + #128 STK[1]=#0 STK[2]=rsp + #132 STK[3]=rsp + #120 STK[4]=rsp + #164
>         # java.lang.AbstractStringBuilder::putStringAt @ bci:15 (line 1754) L[0]=rsp + #0 L[1]=rsp + #120 L[2]=rsp + #64
>         # java.lang.AbstractStringBuilder::append @ bci:30 (line 592) L[0]=rsp + #0 L[1]=rsp + #64 L[2]=rsp + #28
>         # java.lang.StringBuilder::append @ bci:2 (line 179) L[0]=rsp + #0 L[1]=rsp + #64
>         # java.lang.StringBuilder::append @ bci:5 (line 173) L[0]=rsp + #0 L[1]=rsp + #32
>         # sun.util.locale.LocaleExtensions::toID @ bci:100 (line 206) L[0]=RBP L[1]=rsp + #0 L[2]=rsp + #8 L[3]=#ScObj0 L[4]=rsp + #16 L[5]=rsp + #24 L[6]=rsp + #32
>         # ScObj0 java/util/TreeMap$EntryIterator={ [expectedModCount :0]=rsp + #140, [next :1]=rsp + #176, [lastReturned :2]=rsp + #16, [this$0 :3]=rsp + #168 }
> 
> 
> Unfortunately I was not able to create standalone test - it seems requires very particular frequencies of executed paths and used features/flags. The fix was verified with compilation replay file from the bug report.
> 
> I am running testing and will let you know results.

Thank you, Christian and Emanuel for reviews

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PR Comment: https://git.openjdk.org/jdk/pull/23938#issuecomment-2707175188