[Backport] [Oracle GraalVM] [GR-69950] Backport to 23.1: Restrict applicability of RemoveOpaqueValuePhase.

[bulasevich]

This PR backports:

• [GR-52596] Restrict applicability of RemoveOpaqueValuePhase. oracle/graal#8571

Conflicts: Minor import section issue:

import jdk.graal.compiler.nodes.GraphState.StageFlag;
->
import org.graalvm.compiler.nodes.GraphState.StageFlag;

Closes: #237

[Karm]

Hello @bulasevich, do you have any more intel on the PR than the diff itself? The original PR seems one of those with an empty body :-(

[bulasevich]

Hello @bulasevich, do you have any more intel on the PR than the diff itself? The original PR seems one of those with an empty body :-(

Hi Karm, I don’t have any additional info beyond the diff either. I read the changes that it formalize the phase ordering, RemoveOpaqueValuePhase is now constrained to run once and only after LOW_TIER_LOWERING. It makes sense. In general, tightening the ordering helps phases avoid interfering with each other.

[simonis]

Looks reasonable. Thanks.

[zakkak]

Thank you @bulasevich