[lworld] Integrated: 8337210: [lworld] Incorrect IC check leads to continuous cache misses

[Tobias Hartmann]

On Thu, 25 Jul 2024 13:21:37 GMT, Tobias Hartmann <thartmann at openjdk.org> wrote:

> Fixes an incorrect merge of [JDK-8322630](https://bugs.openjdk.org/browse/JDK-8322630) into Valhalla, breaking IC miss resolution and leading to continuous re-resolution of IC calls.
> 
> Incorrect IC check:
> 
>    0x7f9184adfd04:	mov    0x8(%rsi),%r10d
>    0x7f9184adfd08:	cmp    %r10,%rax
>    0x7f9184adfd0b:	jne    0x7f918465b520
> 
> 
> Correct IC check:
> 
>   0x7f2b90ae1d04:   mov    0x8(%rsi),%r10d
>   0x7f2b90ae1d08:   cmp    0x8(%rax),%r10d
>   0x7f2b90ae1d0c:   jne    0x00007f2b9065a820
> 
> 
> I intentionally left out the test that reproduces this because it's a very specific issue and the test would require parsing the output of `-XX:+TraceCallFixup` which is error prone (stress flags might trigger resolution unexpectedly).
> 
> Thanks to @chhagedorn for helping to narrow this down!
> 
> Thanks,
> Tobias

This pull request has now been integrated.

Changeset: a01f6daf
Author:    Tobias Hartmann <thartmann at openjdk.org>
URL:       https://git.openjdk.org/valhalla/commit/a01f6daf1485d882e8810c3d8c3d108f5bbf477d
Stats:     20 lines in 3 files changed: 0 ins; 18 del; 2 mod

8337210: [lworld] Incorrect IC check leads to continuous cache misses

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PR: https://git.openjdk.org/valhalla/pull/1182