[GR-61766] IV: add intact API.

PullRequest: graal/19971

Author: davleopo

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/nodes/loop/BasicInductionVariable.java

@@ -222,4 +222,10 @@ public String toString(IVToStringVerbosity verbosity) {
     public ValueNode entryTripValue() {
         return init;
     }
+
+    @Override
+    public boolean structuralIntegrityValid() {
+        return phi.isAlive() && init.isAlive() && rawStride.isAlive() && op.isAlive();
+    }
+
 }

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/nodes/loop/CountedLoopInfo.java

@@ -150,6 +150,13 @@ protected CountedLoopInfo(Loop loop, InductionVariable limitCheckedIV, IfNode if
         this.unsigned = unsigned;
     }
 
+    /**
+     * See {@link InductionVariable#structuralIntegrityValid()}.
+     */
+    public boolean countedIntegrityValid() {
+        return limitCheckedIV.structuralIntegrityValid() && limit.isAlive() && body.isAlive() && ifNode.isAlive();
+    }
+
     /**
      * Returns the induction variable compared against the limit node. For a loop like
      *

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/nodes/loop/DerivedConvertedInductionVariable.java

@@ -41,6 +41,11 @@ public DerivedConvertedInductionVariable(Loop loop, InductionVariable base, Stam
         this.value = value;
     }
 
+    @Override
+    public boolean structuralIntegrityValid() {
+        return super.structuralIntegrityValid() && value.isAlive();
+    }
+
     @Override
     public ValueNode valueNode() {
         return value;

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/nodes/loop/DerivedInductionVariable.java

@@ -62,6 +62,11 @@ public InductionVariable duplicateWithNewInit(ValueNode newInit) {
         return copy(newBase, copyValue(newBase, false/* no gvn */));
     }
 
+    @Override
+    public boolean structuralIntegrityValid() {
+        return base.structuralIntegrityValid();
+    }
+
     public abstract ValueNode copyValue(InductionVariable newBase);
 
     public abstract ValueNode copyValue(InductionVariable newBase, boolean gvn);

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/nodes/loop/DerivedOffsetInductionVariable.java

@@ -49,6 +49,11 @@ public DerivedOffsetInductionVariable(Loop loop, InductionVariable base, ValueNo
         this.value = value;
     }
 
+    @Override
+    public boolean structuralIntegrityValid() {
+        return super.structuralIntegrityValid() && offset.isAlive() && value.isAlive();
+    }
+
     public ValueNode getOffset() {
         return offset;
     }

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/nodes/loop/DerivedScaledInductionVariable.java

@@ -53,6 +53,11 @@ public DerivedScaledInductionVariable(Loop loop, InductionVariable base, NegateN
         this.value = value;
     }
 
+    @Override
+    public boolean structuralIntegrityValid() {
+        return super.structuralIntegrityValid() && scale.isAlive() && value.isAlive();
+    }
+
     public ValueNode getScale() {
         return scale;
     }

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/nodes/loop/InductionVariable.java

@@ -192,6 +192,12 @@ public enum IVToStringVerbosity {
         NUMERIC
     }
 
+    /**
+     * Determines if the components of this IV are structurally intact, i.e., part of a graph, not
+     * deleted etc.
+     */
+    public abstract boolean structuralIntegrityValid();
+
     public abstract String toString(IVToStringVerbosity verbosity);
 
     @Override