Create prologue/epilogue markers lazily

Author: Christian Wimmer

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/nodes/CFunctionEpilogueNode.java

@@ -55,16 +55,18 @@ public final class CFunctionEpilogueNode extends AbstractStateSplit implements L
     public CFunctionEpilogueNode(int oldThreadStatus) {
         super(TYPE, StampFactory.forVoid());
         this.oldThreadStatus = oldThreadStatus;
-        marker = new CFunctionEpilogueMarker();
     }
 
     @Override
     protected void afterClone(Node other) {
         super.afterClone(other);
-        marker = new CFunctionEpilogueMarker();
+        assert marker == null : "Marker must be unique";
     }
 
     public CFunctionEpilogueMarker getMarker() {
+        if (marker == null) {
+            marker = new CFunctionEpilogueMarker();
+        }
         return marker;
     }
 

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/nodes/CFunctionPrologueNode.java

@@ -62,28 +62,32 @@ public final class CFunctionPrologueNode extends FixedWithNextNode implements Lo
 
     private final int newThreadStatus;
     /**
-     * The marker object prevents value numbering of the node. This means that the marker must be a
-     * unique object per node, even after node cloning (e.g., because of method inlining).
-     * Therefore, {@link #afterClone} properly re-initializes the field to a new marker instance.
-     *
-     * The marker is also used for LIR frame state verification, to ensure we have a proper matching
-     * of prologue and epilogue and no unexpected machine code while the thread is in Native state.
+     * The marker is used for LIR frame state verification, to ensure we have a proper matching of
+     * prologue and epilogue and no unexpected machine code while the thread is in Native state.
      */
     private CFunctionPrologueMarker marker;
 
     public CFunctionPrologueNode(int newThreadStatus) {
         super(TYPE, StampFactory.forVoid());
         this.newThreadStatus = newThreadStatus;
-        marker = new CFunctionPrologueMarker(newThreadStatus);
     }
 
     @Override
     protected void afterClone(Node other) {
         super.afterClone(other);
-        marker = new CFunctionPrologueMarker(newThreadStatus);
+        /*
+         * Note that this method is invoked by the regular method inlining, but not by the
+         * PEGraphDecoder. So the method inlining before analysis, as well as the trivial method
+         * inlining before compilation, do not invoke this method. So it is only suitable for
+         * assertion checking.
+         */
+        assert marker == null : "Marker must be unique";
     }
 
     public CFunctionPrologueMarker getMarker() {
+        if (marker == null) {
+            marker = new CFunctionPrologueMarker(newThreadStatus);
+        }
         return marker;
     }