[GR-35824] Backport 21.3 : Partial Escape Do not update existing stat…

…e mappings. PullRequest: graal/10602
oracle · Dec 16, 2021 · cf58bea · cf58bea
2 parents 406551b + 8b629ec
commit cf58bea
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Showing 2 changed files with 52 additions and 3 deletions.
diff --git a/....graalvm.compiler.virtual/src/org/graalvm/compiler/virtual/phases/ea/GraphEffectList.java b/....graalvm.compiler.virtual/src/org/graalvm/compiler/virtual/phases/ea/GraphEffectList.java
@@ -48,6 +48,7 @@
 import org.graalvm.compiler.nodes.memory.MemoryKill;
 import org.graalvm.compiler.nodes.util.GraphUtil;
 import org.graalvm.compiler.nodes.virtual.EscapeObjectState;
+import org.graalvm.compiler.virtual.nodes.VirtualObjectState;
 import org.graalvm.compiler.phases.common.DeadCodeEliminationPhase;
 
 public final class GraphEffectList extends EffectList {
@@ -168,8 +169,8 @@ public void initializePhiInput(PhiNode node, int index, ValueNode value) {
     }
 
     /**
-     * Adds a virtual object's state to the given frame state. If the given reusedVirtualObjects set
-     * contains the virtual object then old states for this object will be removed.
+     * Adds a virtual object's state to the given frame state. If the given frame state contains the
+     * virtual object then old states for this object will be removed.
      *
      * @param node The frame state to which the state should be added.
      * @param state The virtual object state to add.
@@ -197,6 +198,29 @@ public boolean isVisible() {
         });
     }
 
+    /**
+     * Update a virtual object mapping for the given {@link VirtualObjectState} with a new value.
+     *
+     * @param state The virtual state previously constructed.
+     * @param field The field to update its value.
+     * @param newValue The new value of the field.
+     */
+    public void updateVirtualMapping(VirtualObjectState state, int field, ValueNode newValue) {
+        add("add virtual mapping", new Effect() {
+            @Override
+            public void apply(StructuredGraph graph, ArrayList<Node> obsoleteNodes) {
+                if (state.isAlive()) {
+                    state.values().set(field, graph.addOrUniqueWithInputs(newValue));
+                }
+            }
+
+            @Override
+            public boolean isVisible() {
+                return false;
+            }
+        });
+    }
+
     /**
      * Removes the given fixed node from the control flow and deletes it.
      *

diff --git a/...lvm.compiler.virtual/src/org/graalvm/compiler/virtual/phases/ea/PartialEscapeClosure.java b/...lvm.compiler.virtual/src/org/graalvm/compiler/virtual/phases/ea/PartialEscapeClosure.java
@@ -43,6 +43,7 @@
 import org.graalvm.compiler.debug.GraalError;
 import org.graalvm.compiler.graph.Node;
 import org.graalvm.compiler.graph.NodeBitMap;
+import org.graalvm.compiler.graph.NodeInputList;
 import org.graalvm.compiler.graph.Position;
 import org.graalvm.compiler.nodes.spi.Canonicalizable;
 import org.graalvm.compiler.nodes.AbstractEndNode;
@@ -74,6 +75,7 @@
 import org.graalvm.compiler.nodes.spi.VirtualizerTool;
 import org.graalvm.compiler.nodes.virtual.AllocatedObjectNode;
 import org.graalvm.compiler.nodes.virtual.EnsureVirtualizedNode;
+import org.graalvm.compiler.nodes.virtual.EscapeObjectState;
 import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;
 import org.graalvm.compiler.virtual.nodes.VirtualObjectState;
 
@@ -440,7 +442,30 @@ private static FrameState getUniqueFramestate(NodeWithState nodeWithState, Frame
     }
 
     private void addVirtualMappings(FrameState frameState, EconomicSet<VirtualObjectNode> virtual, BlockT state, GraphEffectList effects) {
-        for (VirtualObjectNode obj : virtual) {
+        object: for (VirtualObjectNode obj : virtual) {
+            /*
+             * Look for existing mappings: Update a virtual object mapping for the given {@link
+             * VirtualObjectState} with a new value. This can be necessary in iterative escape
+             * analysis where a previous iteration already virtualized an object. We must not update
+             * such mappings if no new virtualization occurred. Updating them would create invalid
+             * framestate - virtualization mappings of constructor written fields.
+             */
+            for (int i = 0; i < frameState.virtualObjectMappingCount(); i++) {
+                EscapeObjectState mapping = frameState.virtualObjectMappingAt(i);
+                if (mapping.object() == obj && mapping instanceof VirtualObjectState) {
+                    VirtualObjectState virtualState = (VirtualObjectState) mapping;
+                    NodeInputList<ValueNode> values = virtualState.values();
+                    for (int v = 0; v < values.size(); v++) {
+                        ValueNode value = values.get(v);
+                        ValueNode alias = getAlias(value);
+                        if (alias != value) {
+                            effects.updateVirtualMapping(virtualState, v, alias);
+                        }
+                    }
+                    continue object;
+                }
+            }
+
             effects.addVirtualMapping(frameState, state.getObjectState(obj).createEscapeObjectState(debug, tool.getMetaAccessExtensionProvider(), obj));
         }
     }