small size optimization for typestate

Author: d-kozak

substratevm/src/com.oracle.graal.pointsto/src/com/oracle/graal/pointsto/AnalysisPolicy.java

@@ -49,6 +49,7 @@
 import com.oracle.graal.pointsto.typestate.TypeState;
 import com.oracle.graal.pointsto.typestore.ArrayElementsTypeStore;
 import com.oracle.graal.pointsto.typestore.FieldTypeStore;
+import com.oracle.graal.pointsto.util.AnalysisError;
 import com.oracle.svm.common.meta.MultiMethod;
 
 import jdk.graal.compiler.options.OptionValues;
@@ -72,6 +73,8 @@ public abstract class AnalysisPolicy {
     protected final boolean useConservativeUnsafeAccess;
     private final int parsingContextMaxDepth;
     private final boolean trackAccessChain;
+    protected final int multiTypeStateArrayBitSetThreshold;
+    protected final int multiTypeStateArrayBitSetIntersectionSpeculationThreshold;
 
     public AnalysisPolicy(OptionValues options) {
         this.options = options;
@@ -88,6 +91,11 @@ public AnalysisPolicy(OptionValues options) {
         useConservativeUnsafeAccess = PointstoOptions.UseConservativeUnsafeAccess.getValue(options);
         trackAccessChain = PointstoOptions.TrackAccessChain.getValue(options);
         parsingContextMaxDepth = PointstoOptions.ParsingContextMaxDepth.getValue(options);
+        multiTypeStateArrayBitSetThreshold = PointstoOptions.MultiTypeStateArrayBitSetThreshold.getValue(options);
+        multiTypeStateArrayBitSetIntersectionSpeculationThreshold = PointstoOptions.MultiTypeStateArrayBitSetIntersectionSpeculationThreshold.getValue(options);
+        AnalysisError.guarantee(multiTypeStateArrayBitSetIntersectionSpeculationThreshold >= multiTypeStateArrayBitSetThreshold,
+                        "The MultiTypeStateArrayBitSetIntersectionSpeculationThreshold (%d) should always be larger than MultiTypeStateArrayBitSetThreshold (%d)",
+                        multiTypeStateArrayBitSetIntersectionSpeculationThreshold, multiTypeStateArrayBitSetThreshold);
     }
 
     public abstract boolean isContextSensitiveAnalysis();
@@ -306,4 +314,20 @@ public TypeState doSubtraction(PointsToAnalysis bb, SingleTypeState s1, MultiTyp
     protected static boolean areTypesCompatibleForSystemArraycopy(AnalysisType srcType, AnalysisType dstType) {
         return dstType.isAssignableFrom(srcType) || srcType.isAssignableFrom(dstType);
     }
+
+    /**
+     * @return The maximum number of types represented in {@link MultiTypeState} as an array before
+     *         converting to bitset-based implementation.
+     */
+    public int multiTypeStateArrayBitSetThreshold() {
+        return multiTypeStateArrayBitSetThreshold;
+    }
+
+    /**
+     * @return The maximum number of types on which the analysis should speculate that the result
+     *         will be small enough to be array-based.
+     */
+    public int multiTypeStateArrayBitSetIntersectionSpeculationThreshold() {
+        return multiTypeStateArrayBitSetIntersectionSpeculationThreshold;
+    }
 }

substratevm/src/com.oracle.graal.pointsto/src/com/oracle/graal/pointsto/api/PointstoOptions.java

@@ -111,6 +111,13 @@ public class PointstoOptions {
     @Option(help = "The maximum number of types recorded in a type flow. -1 indicates no limitation.")//
     public static final OptionKey<Integer> TypeFlowSaturationCutoff = new OptionKey<>(20);
 
+    @Option(help = "The maximum number of types that will be represented as an array before switching to bitsets. By default 20 to align with TypeFlowSaturationCutoff. " +
+                    "Note that we can also disable the array-based handling completely by setting the threshold to zero.")//
+    public static final OptionKey<Integer> MultiTypeStateArrayBitSetThreshold = new OptionKey<>(20);
+
+    @Option(help = "The maximum number of types on which the analysis should speculate that the result will be small enough to be array-based.")//
+    public static final OptionKey<Integer> MultiTypeStateArrayBitSetIntersectionSpeculationThreshold = new OptionKey<>(32);
+
     @Option(help = "Enable the type flow saturation analysis performance optimization.")//
     public static final OptionKey<Boolean> RemoveSaturatedTypeFlows = new OptionKey<>(true) {
         @Override

substratevm/src/com.oracle.graal.pointsto/src/com/oracle/graal/pointsto/flow/context/bytecode/ContextSensitiveMultiTypeState.java

@@ -32,11 +32,11 @@
 import com.oracle.graal.pointsto.PointsToAnalysis;
 import com.oracle.graal.pointsto.flow.context.object.AnalysisObject;
 import com.oracle.graal.pointsto.meta.AnalysisType;
-import com.oracle.graal.pointsto.typestate.MultiTypeState;
+import com.oracle.graal.pointsto.typestate.MultiTypeStateWithBitSet;
 import com.oracle.graal.pointsto.typestate.PointsToStats;
 import com.oracle.graal.pointsto.typestate.TypeState;
 
-public class ContextSensitiveMultiTypeState extends MultiTypeState {
+public class ContextSensitiveMultiTypeState extends MultiTypeStateWithBitSet {
 
     /** The objects of this type state. */
     protected final AnalysisObject[] objects;