[lworld] Integrated: 8329196: [lworld] More fixes to value object construction in C2

[Tobias Hartmann]

On Wed, 27 Mar 2024 15:54:40 GMT, Tobias Hartmann <thartmann at openjdk.org> wrote:

> Follow-up from [JDK-8325660](https://bugs.openjdk.org/browse/JDK-8325660). We can't rely on `GraphKit::replace_in_map` to reliably replace an InlineTypeNode that is initialized in the constructor in the caller map because there can be data flow merges. Instead, we need to explicitly update the node in the exit map. I added corresponding regression tests.
> 
> I also noticed that we are extensively cloning InlineTypeNodes during parsing, which often leads to an explosion of redundant nodes that then need to be removed. I added `InlineTypeNode::clone_if_required` to mitigate this, this can probably be further improved (I added corresponding ToDo's).
> 
> There are still issues with deoptimization from the constructor (`-XX:+DeoptimizeALot`). I'll address these in another fix.
> 
> I also disabled an IR rule in `TestZGCBarrierElision`. The issue will be fixed by [JDK-8329234](https://bugs.openjdk.org/browse/JDK-8329234).
> 
> Thanks,
> Tobias

This pull request has now been integrated.

Changeset: e01ec832
Author:    Tobias Hartmann <thartmann at openjdk.org>
URL:       https://git.openjdk.org/valhalla/commit/e01ec832189453cc302c7ca8915e69bb63a3d4b1
Stats:     304 lines in 14 files changed: 249 ins; 10 del; 45 mod

8329196: [lworld] More fixes to value object construction in C2

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PR: https://git.openjdk.org/valhalla/pull/1064