diff --git a/build.gradle b/build.gradle
index ebebe33..4caf5fa 100644
--- a/build.gradle
+++ b/build.gradle
@@ -75,6 +75,7 @@
 dependencies {
     compile 'net.sf.jopt-simple:jopt-simple:4.6'
     compile group: 'com.google.guava', name: 'guava', version: '19.0'
+    compile group: 'it.unimi.dsi', name: 'fastutil', version: '7.2.0'
     compile group: 'org.apache.commons', name: 'commons-compress', version: '1.12'
     compile group: 'org.ow2.asm', name: 'asm', version: '5.1'
     compile group: 'org.ow2.asm', name: 'asm-commons', version: '5.1'
@@ -305,7 +306,7 @@
 }
 
 task createJctfTests(type: Exec) {
-    def outputDir = "build/generated/test/java/com/android/tools/r8/art"
+    def outputDir = "build/generated/test/java/com/android/tools/r8/jctf"
     def script = "scripts/create-jctf-tests.sh"
     inputs.file script
     outputs.dir outputDir
@@ -659,10 +660,10 @@
     }
     // TODO(tamaskenez) enable jctf on all_tests when consolidated
     if (!project.hasProperty('jctf') && !project.hasProperty('only_jctf')) {
-        exclude "com/android/tools/r8/art/jctf/**"
+        exclude "com/android/tools/r8/jctf/**"
     }
     if (project.hasProperty('only_jctf')) {
-        include "com/android/tools/r8/art/jctf/**"
+        include "com/android/tools/r8/jctf/**"
     }
     if (project.hasProperty('jctf_compile_only')) {
         println "JCTF: compiling only"
diff --git a/scripts/create-jctf-tests.sh b/scripts/create-jctf-tests.sh
index 538f3c3..2f4e91e 100755
--- a/scripts/create-jctf-tests.sh
+++ b/scripts/create-jctf-tests.sh
@@ -26,7 +26,7 @@
 // Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-package com.android.tools.r8.art.jctf.${compilerUnderTest}.${relativePackage};
+package com.android.tools.r8.jctf.${compilerUnderTest}.${relativePackage};
 
 import org.junit.Test;
 import com.android.tools.r8.R8RunArtTestsTest;
@@ -57,14 +57,14 @@
 }
 
 JCTFROOT="third_party/jctf"
-DESTINATIONDIR="build/generated/test/java/com/android/tools/r8/art"
+DESTINATIONDIR="build/generated/test/java/com/android/tools/r8/jctf"
 
 if [ ! -e $JCTFROOT ]; then
   echo "Missing jctf tests in $JCTFROOT."
   exit
 fi
 
-for d in $DESTINATIONDIR/jctf/r8 $DESTINATIONDIR/jctf/d8; do
+for d in $DESTINATIONDIR/r8 $DESTINATIONDIR/d8; do
   rm -rf $d
   mkdir -p $d
 done
@@ -86,10 +86,10 @@
   RELATIVE_PACKAGE=$(expr "$PACKAGE" : ".*\.java\.\(.*$\)")
 
   generate_test $PACKAGE.$TESTNAME $TESTCLASSNAME \
-    "$DESTINATIONDIR/jctf/r8/$RELATIVE_TEST_PATH" r8 \
+    "$DESTINATIONDIR/r8/$RELATIVE_TEST_PATH" r8 \
     $CLASSFILE $RELATIVE_PACKAGE
   generate_test $PACKAGE.$TESTNAME $TESTCLASSNAME \
-    "$DESTINATIONDIR/jctf/d8/$RELATIVE_TEST_PATH" d8 \
+    "$DESTINATIONDIR/d8/$RELATIVE_TEST_PATH" d8 \
     $CLASSFILE $RELATIVE_PACKAGE
 done
 
diff --git a/src/main/java/com/android/tools/r8/dex/DexFileReader.java b/src/main/java/com/android/tools/r8/dex/DexFileReader.java
index a38d397..627d106 100644
--- a/src/main/java/com/android/tools/r8/dex/DexFileReader.java
+++ b/src/main/java/com/android/tools/r8/dex/DexFileReader.java
@@ -50,8 +50,8 @@
 import com.android.tools.r8.graph.DexValue.DexValueString;
 import com.android.tools.r8.graph.OffsetToObjectMapping;
 import com.android.tools.r8.logging.Log;
-import com.android.tools.r8.utils.IntHashMap;
-import com.android.tools.r8.utils.InternalResource;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.nio.ShortBuffer;
@@ -91,10 +91,10 @@
   private OffsetToObjectMapping indexedItems = new OffsetToObjectMapping();
 
   // Mapping from offset to code item;
-  private IntHashMap<DexCode> codes = new IntHashMap<>();
+  private Int2ObjectMap<DexCode> codes = new Int2ObjectOpenHashMap<>();
 
   // Mapping from offset to dex item;
-  private IntHashMap<Object> offsetMap = new IntHashMap<>();
+  private Int2ObjectMap<Object> offsetMap = new Int2ObjectOpenHashMap<>();
 
   // Factory to canonicalize certain dexitems.
   private final DexItemFactory dexItemFactory;
@@ -140,7 +140,9 @@
   }
 
   private DexTypeList typeListAt(int offset) {
-    if (offset == 0) return DexTypeList.empty();
+    if (offset == 0) {
+      return DexTypeList.empty();
+    }
     return (DexTypeList) cacheAt(offset, this::parseTypeList);
   }
 
@@ -358,9 +360,13 @@
   }
 
   private <T> Object cacheAt(int offset, Supplier<T> function) {
-    if (offset == 0) return null;  // return null for offset zero.
+    if (offset == 0) {
+      return null;  // return null for offset zero.
+    }
     Object result = offsetMap.get(offset);
-    if (result != null) return result;  // return the cached result.
+    if (result != null) {
+      return result;  // return the cached result.
+    }
     // Cache is empty so parse the structure.
     file.position(offset);
     result = function.get();
@@ -812,7 +818,7 @@
   private static void populateMethodHandles(DexFileReader reader) {
     Segment segment = reader.lookupSegment(Constants.TYPE_METHOD_HANDLE_ITEM);
     reader.indexedItems.initializeMethodHandles(segment.size);
-    for (int i = 0; i < segment.size; i++){
+    for (int i = 0; i < segment.size; i++) {
       reader.indexedItems.setMethodHandle(i, reader.methodHandleAt(i));
     }
   }
@@ -820,7 +826,7 @@
   private static void populateCallSites(DexFileReader reader) {
     Segment segment = reader.lookupSegment(Constants.TYPE_CALL_SITE_ID_ITEM);
     reader.indexedItems.initializeCallSites(segment.size);
-    for (int i = 0; i < segment.size; i++){
+    for (int i = 0; i < segment.size; i++) {
       reader.indexedItems.setCallSites(i, reader.callSiteAt(i));
     }
   }
@@ -828,7 +834,7 @@
   private static void populateTypes(DexFileReader reader) {
     Segment segment = reader.lookupSegment(Constants.TYPE_TYPE_ID_ITEM);
     reader.indexedItems.initializeTypes(segment.size);
-    for (int i = 0; i < segment.size; i++){
+    for (int i = 0; i < segment.size; i++) {
       reader.indexedItems.setType(i, reader.typeAt(i));
     }
   }
@@ -836,7 +842,7 @@
   private static void populateFields(DexFileReader reader) {
     Segment segment = reader.lookupSegment(Constants.TYPE_FIELD_ID_ITEM);
     reader.indexedItems.initializeFields(segment.size);
-    for (int i = 0; i < segment.size; i++){
+    for (int i = 0; i < segment.size; i++) {
       reader.indexedItems.setField(i, reader.fieldAt(i));
     }
   }
@@ -844,7 +850,7 @@
   private static void populateProtos(DexFileReader reader) {
     Segment segment = reader.lookupSegment(Constants.TYPE_PROTO_ID_ITEM);
     reader.indexedItems.initializeProtos(segment.size);
-    for (int i = 0; i < segment.size; i++){
+    for (int i = 0; i < segment.size; i++) {
       reader.indexedItems.setProto(i, reader.protoAt(i));
     }
   }
@@ -852,7 +858,7 @@
   private static void populateMethods(DexFileReader reader) {
     Segment segment = reader.lookupSegment(Constants.TYPE_METHOD_ID_ITEM);
     reader.indexedItems.initializeMethods(segment.size);
-    for (int i = 0; i < segment.size; i++){
+    for (int i = 0; i < segment.size; i++) {
       reader.indexedItems.setMethod(i, reader.methodAt(i));
     }
   }
diff --git a/src/main/java/com/android/tools/r8/ir/conversion/LensCodeRewriter.java b/src/main/java/com/android/tools/r8/ir/conversion/LensCodeRewriter.java
index 2d5d803..1eb8707 100644
--- a/src/main/java/com/android/tools/r8/ir/conversion/LensCodeRewriter.java
+++ b/src/main/java/com/android/tools/r8/ir/conversion/LensCodeRewriter.java
@@ -96,7 +96,7 @@
             continue;
           }
           DexMethod actualTarget = graphLense.lookupMethod(invokedMethod, method);
-          Invoke.Type invokeType = getInvokeType(invoke, actualTarget);
+          Invoke.Type invokeType = getInvokeType(invoke, actualTarget, invokedMethod);
           if (actualTarget != invokedMethod || invoke.getType() != invokeType) {
             Invoke newInvoke = Invoke
                 .create(invokeType, actualTarget, null,
@@ -228,16 +228,26 @@
     return methodHandle;
   }
 
-  private Type getInvokeType(InvokeMethod invoke, DexMethod actualTarget) {
+  private Type getInvokeType(InvokeMethod invoke, DexMethod actualTarget,
+      DexMethod originalTarget) {
     if (invoke.isInvokeVirtual() || invoke.isInvokeInterface()) {
       // Get the invoke type of the actual definition.
-      DexClass clazz = appInfo.definitionFor(actualTarget.holder);
-      if (clazz == null) {
+      DexClass newTargetClass = appInfo.definitionFor(actualTarget.holder);
+      if (newTargetClass == null) {
         return invoke.getType();
       } else {
-        return clazz.accessFlags.isInterface()
-            ? Type.INTERFACE
-            : Type.VIRTUAL;
+        DexClass originalTargetClass = appInfo.definitionFor(originalTarget.holder);
+        if (originalTargetClass.isInterface() ^ (invoke.getType() == Type.INTERFACE)) {
+          // The invoke was wrong to start with, so we keep it wrong. This is to ensure we get
+          // the IncompatibleClassChangeError the original invoke would have triggered.
+          return newTargetClass.accessFlags.isInterface()
+              ? Type.VIRTUAL
+              : Type.INTERFACE;
+        } else {
+          return newTargetClass.accessFlags.isInterface()
+              ? Type.INTERFACE
+              : Type.VIRTUAL;
+        }
       }
     } else {
       return invoke.getType();
diff --git a/src/main/java/com/android/tools/r8/ir/optimize/Inliner.java b/src/main/java/com/android/tools/r8/ir/optimize/Inliner.java
index dc2ed67..11548bc 100644
--- a/src/main/java/com/android/tools/r8/ir/optimize/Inliner.java
+++ b/src/main/java/com/android/tools/r8/ir/optimize/Inliner.java
@@ -223,7 +223,10 @@
           InlineAction result = invoke.computeInlining(oracle);
           if (result != null) {
             DexEncodedMethod target = appInfo.lookup(invoke.getType(), invoke.getInvokedMethod());
-            assert target != null;
+            if (target == null) {
+              // The declared target cannot be found so skip inlining.
+              continue;
+            }
             boolean forceInline = target.getOptimizationInfo().forceInline();
             if (!target.isProcessed() && !forceInline) {
               // Do not inline code that was not processed unless we have to force inline.
diff --git a/src/main/java/com/android/tools/r8/ir/regalloc/LinearScanRegisterAllocator.java b/src/main/java/com/android/tools/r8/ir/regalloc/LinearScanRegisterAllocator.java
index e79abc1..f2d039d 100644
--- a/src/main/java/com/android/tools/r8/ir/regalloc/LinearScanRegisterAllocator.java
+++ b/src/main/java/com/android/tools/r8/ir/regalloc/LinearScanRegisterAllocator.java
@@ -470,7 +470,7 @@
     return realRegisterNumberFromAllocated(intervalsRegister);
   }
 
-  int realRegisterNumberFromAllocated(int allocated) {
+  int unadjustedRealRegisterFromAllocated(int allocated) {
     assert allocated != NO_REGISTER;
     assert allocated >= 0;
     int register;
@@ -484,6 +484,11 @@
       // For everything else use the lower numbers.
       register = allocated - numberOfArgumentRegisters - NUMBER_OF_SENTINEL_REGISTERS;
     }
+    return register;
+  }
+
+  int realRegisterNumberFromAllocated(int allocated) {
+    int register = unadjustedRealRegisterFromAllocated(allocated);
     // Adjust for spill registers that turn out to be unused because the value can be
     // rematerialized instead of spilled.
     if (unusedRegisters != null) {
diff --git a/src/main/java/com/android/tools/r8/ir/regalloc/LiveIntervals.java b/src/main/java/com/android/tools/r8/ir/regalloc/LiveIntervals.java
index f1d3b9e..c966813 100644
--- a/src/main/java/com/android/tools/r8/ir/regalloc/LiveIntervals.java
+++ b/src/main/java/com/android/tools/r8/ir/regalloc/LiveIntervals.java
@@ -89,8 +89,12 @@
     }
     // If one of the non-spilled splits uses a register that is higher than U8BIT_MAX we cannot
     // rematerialize it using a ConstNumber instruction and we use spill moves instead of
-    // rematerialization.
-    int max = registerAllocator.realRegisterNumberFromAllocated(getMaxNonSpilledRegister());
+    // rematerialization. We use this check both before and after we have computed the set
+    // of unused registers. We therefore have to be careful to use the same max number for
+    // these computations. We use the unadjusted real register number to make sure that
+    // isRematerializable for the same intervals does not change from one phase of
+    // compilation to the next.
+    int max = registerAllocator.unadjustedRealRegisterFromAllocated(getMaxNonSpilledRegister());
     return max < Constants.U8BIT_MAX;
   }
 
diff --git a/src/main/java/com/android/tools/r8/optimize/DebugStripper.java b/src/main/java/com/android/tools/r8/optimize/DebugStripper.java
index d045f76..998bc8d 100644
--- a/src/main/java/com/android/tools/r8/optimize/DebugStripper.java
+++ b/src/main/java/com/android/tools/r8/optimize/DebugStripper.java
@@ -17,9 +17,10 @@
 import com.android.tools.r8.naming.MemberNaming;
 import com.android.tools.r8.naming.MemberNaming.Range;
 import com.android.tools.r8.naming.MemberNaming.Signature;
-import com.android.tools.r8.utils.HashMapInt;
 import com.android.tools.r8.utils.InternalOptions;
 import com.google.common.collect.ImmutableMap;
+import it.unimi.dsi.fastutil.objects.Reference2IntMap;
+import it.unimi.dsi.fastutil.objects.Reference2IntOpenHashMap;
 import java.util.List;
 
 public class DebugStripper {
@@ -50,6 +51,7 @@
   }
 
   private static class NumberedDebugInfo {
+
     final int numberOfEntries;
     final DexDebugInfo info;
 
@@ -103,7 +105,7 @@
   }
 
   private void processCode(DexEncodedMethod encodedMethod, MemberNaming naming,
-      HashMapInt<DexString> nameCounts) {
+      Reference2IntMap<DexString> nameCounts) {
     if (encodedMethod.getCode() == null) {
       return;
     }
@@ -118,7 +120,7 @@
     if (options.skipDebugLineNumberOpt) {
       startLine = originalInfo.startLine;
     } else {
-      int nameCount = nameCounts.get(name);
+      int nameCount = nameCounts.getInt(name);
       if (nameCount == USED_ONCE) {
         isUsedOnce = true;
         startLine = 0;
@@ -132,7 +134,7 @@
     DexDebugInfo newInfo = numberedInfo.info;
     if (!options.skipDebugLineNumberOpt) {
       // Fix up the line information.
-      int previousCount = nameCounts.get(name);
+      int previousCount = nameCounts.getInt(name);
       nameCounts.put(name, previousCount + numberedInfo.numberOfEntries);
       // If we don't actually need line information and there are no debug entries, throw it away.
       if (newInfo != null && isUsedOnce && newInfo.events.length == 0) {
@@ -147,7 +149,7 @@
   }
 
   private void processMethod(DexEncodedMethod method, ClassNaming classNaming,
-      HashMapInt<DexString> nameCounts) {
+      Reference2IntMap<DexString> nameCounts) {
     MemberNaming naming = null;
     if (classNaming != null) {
       Signature renamedSignature = classNameMapper.getRenamedMethodSignature(method.method);
@@ -157,7 +159,7 @@
   }
 
   private void processMethods(DexEncodedMethod[] methods, ClassNaming naming,
-      HashMapInt<DexString> nameCounts) {
+      Reference2IntMap<DexString> nameCounts) {
     if (methods == null) {
       return;
     }
@@ -172,14 +174,14 @@
     }
     String name = descriptorToName(clazz.type.toDescriptorString());
     ClassNaming naming = classNameMapper == null ? null : classNameMapper.getClassNaming(name);
-    HashMapInt<DexString> nameCounts = new HashMapInt<>();
+    Reference2IntMap<DexString> nameCounts = new Reference2IntOpenHashMap<>();
     setIntialNameCounts(nameCounts, clazz.directMethods());
     setIntialNameCounts(nameCounts, clazz.virtualMethods());
     processMethods(clazz.directMethods(), naming, nameCounts);
     processMethods(clazz.virtualMethods(), naming, nameCounts);
   }
 
-  private void setIntialNameCounts(HashMapInt<DexString> nameCounts,
+  private void setIntialNameCounts(Reference2IntMap<DexString> nameCounts,
       DexEncodedMethod[] methods) {
     for (DexEncodedMethod method : methods) {
       if (nameCounts.containsKey(method.method.name)) {
diff --git a/src/main/java/com/android/tools/r8/shaking/SimpleClassMerger.java b/src/main/java/com/android/tools/r8/shaking/SimpleClassMerger.java
index bc43ae8..a2864e4 100644
--- a/src/main/java/com/android/tools/r8/shaking/SimpleClassMerger.java
+++ b/src/main/java/com/android/tools/r8/shaking/SimpleClassMerger.java
@@ -23,9 +23,6 @@
 import com.android.tools.r8.optimize.InvokeSingleTargetExtractor;
 import com.android.tools.r8.shaking.Enqueuer.AppInfoWithLiveness;
 import com.android.tools.r8.utils.FieldSignatureEquivalence;
-import com.android.tools.r8.utils.HashMapInt;
-import com.android.tools.r8.utils.IdentityHashMapInt;
-import com.android.tools.r8.utils.IntIntHashMap;
 import com.android.tools.r8.utils.MethodSignatureEquivalence;
 import com.android.tools.r8.utils.Timing;
 import com.google.common.base.Equivalence;
@@ -33,6 +30,10 @@
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Iterators;
 import com.google.common.collect.Sets;
+import it.unimi.dsi.fastutil.ints.Int2IntMap;
+import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
+import it.unimi.dsi.fastutil.objects.Reference2IntMap;
+import it.unimi.dsi.fastutil.objects.Reference2IntOpenHashMap;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -274,7 +275,7 @@
     }
 
     private <T> Set<T> mergeArrays(T[] one, T[] other) {
-      Set<T> merged = new LinkedHashSet<T>();
+      Set<T> merged = new LinkedHashSet<>();
       Collections.addAll(merged, one);
       Collections.addAll(merged, other);
       return merged;
@@ -513,22 +514,26 @@
 
   private static class CollisionDetector {
 
+    private static int NOT_FOUND = 1 << (Integer.SIZE - 1);
+
     // TODO(herhut): Maybe cache seenPositions for target classes.
-    private final Map<DexString, IntIntHashMap> seenPositions = new IdentityHashMap<>();
-    private final HashMapInt<DexProto> targetProtoCache;
-    private final HashMapInt<DexProto> sourceProtoCache;
+    private final Map<DexString, Int2IntMap> seenPositions = new IdentityHashMap<>();
+    private final Reference2IntMap<DexProto> targetProtoCache;
+    private final Reference2IntMap<DexProto> sourceProtoCache;
     private final DexType source, target;
-    private final Set<DexMethod> invokes;
+    private final Collection<DexMethod> invokes;
     private final Map<DexType, DexType> substituions;
 
-    private CollisionDetector(DexType source, DexType target, Set<DexMethod> invokes,
+    private CollisionDetector(DexType source, DexType target, Collection<DexMethod> invokes,
         Map<DexType, DexType> substitutions) {
       this.source = source;
       this.target = target;
       this.invokes = invokes;
       this.substituions = substitutions;
-      this.targetProtoCache = new IdentityHashMapInt<>(invokes.size() / 2);
-      this.sourceProtoCache = new IdentityHashMapInt<>(invokes.size() / 2);
+      this.targetProtoCache = new Reference2IntOpenHashMap<>(invokes.size() / 2);
+      this.targetProtoCache.defaultReturnValue(NOT_FOUND);
+      this.sourceProtoCache = new Reference2IntOpenHashMap<>(invokes.size() / 2);
+      this.sourceProtoCache.defaultReturnValue(NOT_FOUND);
     }
 
     boolean mayCollide() {
@@ -538,11 +543,11 @@
         return false;
       }
       for (DexMethod method : invokes) {
-        IntIntHashMap positionsMap = seenPositions.get(method.name);
+        Int2IntMap positionsMap = seenPositions.get(method.name);
         if (positionsMap != null) {
           int arity = method.proto.parameters.values.length;
-          if (positionsMap.containsKey(arity)) {
-            int previous = positionsMap.get(arity);
+          int previous = positionsMap.get(arity);
+          if (previous != NOT_FOUND) {
             assert previous != 0;
             int positions = computePositionsFor(method.proto, source, sourceProtoCache,
                 substituions);
@@ -561,55 +566,58 @@
         int arity = parameters.length;
         int positions = computePositionsFor(method.proto, target, targetProtoCache, substituions);
         if (positions != 0) {
-          IntIntHashMap positionsMap =
-              seenPositions.computeIfAbsent(method.name, k -> new IntIntHashMap());
+          Int2IntMap positionsMap =
+              seenPositions.computeIfAbsent(method.name, k -> {
+                Int2IntMap result = new Int2IntOpenHashMap();
+                result.defaultReturnValue(NOT_FOUND);
+                return result;
+              });
           int value = 0;
-          if (positionsMap.containsKey(arity)) {
-            value = positionsMap.get(arity);
+          int previous = positionsMap.get(arity);
+          if (previous != NOT_FOUND) {
+            value = previous;
           }
           value |= positions;
           positionsMap.put(arity, value);
         }
       }
-      int filled = 0;
-      for (IntIntHashMap pos : seenPositions.values()) {
-        filled += pos.size();
-      }
+
     }
 
     private int computePositionsFor(DexProto proto, DexType type,
-        HashMapInt<DexProto> cache, Map<DexType, DexType> substituions) {
-      if (cache.containsKey(proto)) {
-        return cache.get(proto);
+        Reference2IntMap<DexProto> cache, Map<DexType, DexType> substitutions) {
+      int result = cache.getInt(proto);
+      if (result != NOT_FOUND) {
+        return result;
       }
-      int result = 0;
-      int bits = 0;
+      result = 0;
+      int bitsUsed = 0;
       int accumulator = 0;
       for (DexType aType : proto.parameters.values) {
-        if (substituions != null) {
+        if (substitutions != null) {
           // Substitute the type with the already merged class to estimate what it will
           // look like.
-          while (substituions.containsKey(aType)) {
-            aType = substituions.get(aType);
+          while (substitutions.containsKey(aType)) {
+            aType = substitutions.get(aType);
           }
         }
         accumulator <<= 1;
-        bits++;
+        bitsUsed++;
         if (aType == type) {
           accumulator |= 1;
         }
-        // Handle overflow on 32 bit boundary.
-        if (bits == Integer.SIZE) {
+        // Handle overflow on 31 bit boundary.
+        if (bitsUsed == Integer.SIZE - 1) {
           result |= accumulator;
           accumulator = 0;
-          bits = 0;
+          bitsUsed = 0;
         }
       }
       // We also take the return type into account for potential conflicts.
       DexType returnType = proto.returnType;
-      if (substituions != null) {
-        while (substituions.containsKey(returnType)) {
-          returnType = substituions.get(returnType);
+      if (substitutions != null) {
+        while (substitutions.containsKey(returnType)) {
+          returnType = substitutions.get(returnType);
         }
       }
       accumulator <<= 1;
diff --git a/src/main/java/com/android/tools/r8/utils/HashMapInt.java b/src/main/java/com/android/tools/r8/utils/HashMapInt.java
deleted file mode 100644
index 7e91644..0000000
--- a/src/main/java/com/android/tools/r8/utils/HashMapInt.java
+++ /dev/null
@@ -1,120 +0,0 @@
-// Copyright (c) 2016, the R8 project authors. Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-package com.android.tools.r8.utils;
-
-// Hash map based on open addressing where keys are Objects and values are basic ints.
-// Provides: put, get, and size.
-
-import java.util.Arrays;
-import java.util.Iterator;
-import java.util.Objects;
-
-public class HashMapInt<T> extends SimpleHashMap {
-
-  private Object[] keys;
-  private int[] values;
-
-  public HashMapInt() {
-    super();
-  }
-
-  public HashMapInt(int initialCapacity) {
-    super(initialCapacity);
-  }
-
-  public HashMapInt(int initialCapacity, double loadFactor) {
-    super(initialCapacity, loadFactor);
-  }
-
-  public void put(final T key, final int value) {
-    if (key == null) {
-      throw new RuntimeException("HashMapInt does not support null as key.");
-    }
-    ensureCapacity();
-    basePut(key, value);
-  }
-
-  boolean equals(Object one, Object other) {
-    return one.equals(other);
-  }
-
-  public int get(final T key) {
-    if (key == null) {
-      throw new RuntimeException("HashMapInt does not support null as key.");
-    }
-    int count = 1;
-    int index = firstProbe(key);
-    while (!equals(key, keys[index])) {
-      if (keys[index] == null) {
-        throw new RuntimeException("HashMapInt get only works if key is present.");
-      }
-      index = nextProbe(index, count++);
-    }
-    return values[index];
-  }
-
-  int firstProbe(T key) {
-    return firstProbe(key.hashCode());
-  }
-
-  public boolean containsKey(final T key) {
-    if (key == null) {
-      throw new RuntimeException("HashMapInt does not support null as key.");
-    }
-    int count = 1;
-    for (int index = firstProbe(key); ; index = nextProbe(index, count++)) {
-      Object k = keys[index];
-      if (k == null) {
-        return false;
-      }
-      if (equals(k, key)) {
-        return true;
-      }
-    }
-  }
-
-  private void basePut(final T key, final int value) {
-    int count = 1;
-    int index = firstProbe(key);
-    while ((keys[index] != null) && (keys[index] != key)) {
-      index = nextProbe(index, count++);
-    }
-    if (keys[index] == null) {
-      keys[index] = key;
-      incrementSize();
-    }
-    values[index] = value;
-  }
-
-  @SuppressWarnings("unchecked")
-  public Iterable<Integer> values() {
-    return () -> Arrays.stream(keys).filter(Objects::nonNull).map((key) -> get((T) key)).iterator();
-  }
-
-  @SuppressWarnings("unchecked")
-  public Iterable<T> keys() {
-    return () -> (Iterator<T>) Arrays.stream(keys).filter(Objects::nonNull).iterator();
-  }
-
-  @SuppressWarnings("unchecked")
-  void resize() {
-    final Object[] oldKeys = keys;
-    final int[] oldValues = values;
-    final int oldLength = length();
-    super.resize();
-    // Repopulate.
-    for (int index = 0; index < oldLength; index++) {
-      T key = (T) oldKeys[index];
-      if (key != null) {
-        basePut(key, oldValues[index]);
-      }
-    }
-  }
-
-  void initialize(final int length, final int limit) {
-    super.initialize(length, limit);
-    keys = new Object[length];
-    values = new int[length];
-  }
-}
diff --git a/src/main/java/com/android/tools/r8/utils/IdentityHashMapInt.java b/src/main/java/com/android/tools/r8/utils/IdentityHashMapInt.java
deleted file mode 100644
index 66e62ac..0000000
--- a/src/main/java/com/android/tools/r8/utils/IdentityHashMapInt.java
+++ /dev/null
@@ -1,29 +0,0 @@
-// Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-package com.android.tools.r8.utils;
-
-public class IdentityHashMapInt<T> extends HashMapInt<T> {
-
-  public IdentityHashMapInt() {
-    super();
-  }
-
-  public IdentityHashMapInt(int initialCapacity) {
-    super(initialCapacity);
-  }
-
-  public IdentityHashMapInt(int initialCapacity, double loadFactor) {
-    super(initialCapacity, loadFactor);
-  }
-
-  @Override
-  int firstProbe(T key) {
-    return firstProbe(System.identityHashCode(key));
-  }
-
-  @Override
-  boolean equals(Object one, Object other) {
-    return one == other;
-  }
-}
diff --git a/src/main/java/com/android/tools/r8/utils/IntHashMap.java b/src/main/java/com/android/tools/r8/utils/IntHashMap.java
deleted file mode 100644
index 6a92316..0000000
--- a/src/main/java/com/android/tools/r8/utils/IntHashMap.java
+++ /dev/null
@@ -1,113 +0,0 @@
-// Copyright (c) 2016, the R8 project authors. Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-package com.android.tools.r8.utils;
-
-// Hash map based on open addressing where keys are basic ints and values are Objects.
-// Provides: put, get, and size.
-
-import java.util.Arrays;
-import java.util.Iterator;
-import java.util.Objects;
-import java.util.stream.IntStream;
-
-public class IntHashMap<T> extends SimpleHashMap {
-
-  private int[] keys;
-  private Object[] values;
-
-  public IntHashMap() {
-    super();
-  }
-
-  public IntHashMap(int initialCapacity) {
-    super(initialCapacity);
-  }
-
-  public IntHashMap(int initialCapacity, double loadFactor) {
-    super(initialCapacity, loadFactor);
-  }
-
-  public void put(final int key, final T value) {
-    if (value == null) {
-      throw new RuntimeException("IntHashMap does not support null as value.");
-    }
-    ensureCapacity();
-    basePut(key, value);
-  }
-
-  public T get(final int key) {
-    int count = 1;
-    int index = firstProbe(computeHash(key));
-    // Note that unused entries in keys is 0.
-    // That means we only need to check for value != null when key == 0.
-    while ((keys[index] != key) && (values[index] != null)) {
-      index = nextProbe(index, count++);
-    }
-    assert (keys[index] == key) || (values[index] == null);
-    @SuppressWarnings("unchecked")
-    T result = (T) values[index];
-    return result;
-  }
-
-  private void basePut(final int key, final Object value) {
-    assert value != null;
-    int count = 1;
-    int index = firstProbe(computeHash(key));
-    while ((values[index] != null) && (keys[index] != key)) {
-      index = nextProbe(index, count++);
-    }
-    if (values[index] == null) {
-      keys[index] = key;
-      incrementSize();
-    }
-    values[index] = value;
-    assert value.equals(get(key));
-  }
-
-  void resize() {
-    final int[] oldKeys = keys;
-    final Object[] oldValues = values;
-    final int oldLength = length();
-    super.resize();
-    // Repopulate.
-    for (int index = 0; index < oldLength; index++) {
-      Object value = oldValues[index];
-      if (value != null) {
-        basePut(oldKeys[index], value);
-      }
-    }
-  }
-
-  void initialize(final int length, final int limit) {
-    super.initialize(length, limit);
-    keys = new int[length];
-    values = new Object[length];
-  }
-
-  @SuppressWarnings("unchecked")
-  public Iterable<T> values() {
-    return () -> (Iterator<T>) Arrays.stream(values).filter(Objects::nonNull).iterator();
-  }
-
-  public Iterable<Integer> keys() {
-    if (get(0) != null) {
-      return () -> IntStream.concat(IntStream.of(0), Arrays.stream(keys).filter(i -> i != 0))
-          .iterator();
-    }
-    return () -> Arrays.stream(keys).filter(i -> i != 0 || get(i) != null).distinct().iterator();
-  }
-
-  // Thomas Wang, Integer Hash Functions.
-  // http://www.concentric.net/~Ttwang/tech/inthash.htm
-  private static int computeHash(final int key) {
-    int hash = key;
-    hash = ~hash + (hash << 15);  // hash = (hash << 15) - hash - 1;
-    hash = hash ^ (hash >> 12);
-    hash = hash + (hash << 2);
-    hash = hash ^ (hash >> 4);
-    hash = hash * 2057;  // hash = (hash + (hash << 3)) + (hash << 11);
-    hash = hash ^ (hash >> 16);
-    return hash & 0x3fffffff;
-  }
-}
diff --git a/src/main/java/com/android/tools/r8/utils/IntIntHashMap.java b/src/main/java/com/android/tools/r8/utils/IntIntHashMap.java
deleted file mode 100644
index 03d4911..0000000
--- a/src/main/java/com/android/tools/r8/utils/IntIntHashMap.java
+++ /dev/null
@@ -1,113 +0,0 @@
-// Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-package com.android.tools.r8.utils;
-
-// Hash map based on open addressing where keys are positive basic ints and values are basic ints.
-// Provides: put, get, and size.
-
-import java.util.Arrays;
-
-public class IntIntHashMap extends SimpleHashMap {
-
-  private final int EMPTY_KEY = -1;
-
-  private int[] keys;
-  private int[] values;
-
-  public IntIntHashMap() {
-    super();
-  }
-
-  public IntIntHashMap(int initialCapacity) {
-    super(initialCapacity);
-  }
-
-  public IntIntHashMap(int initialCapacity, double loadFactor) {
-    super(initialCapacity, loadFactor);
-  }
-
-  public void put(final int key, final int value) {
-    if (key < 0) {
-      throw new RuntimeException("IntIntHashMap does not support negative ints as key.");
-    }
-    ensureCapacity();
-    basePut(key, value);
-  }
-
-  public int get(final int key) {
-    if (key < 0) {
-      throw new RuntimeException("IntIntHashMap does not support negative ints as key.");
-    }
-    int count = 1;
-    int index = firstProbe(key);
-    while (key != keys[index]) {
-      if (keys[index] == EMPTY_KEY) {
-        throw new RuntimeException("IntIntHashMap get only works if key is present.");
-      }
-      index = nextProbe(index, count++);
-    }
-    return values[index];
-  }
-
-  public boolean containsKey(final int key) {
-    if (key < 0) {
-      throw new RuntimeException("IntIntHashMap does not support negative ints as key.");
-    }
-    int count = 1;
-    for (int index = firstProbe(key); ; index = nextProbe(index, count++)) {
-      int k = keys[index];
-      if (k == EMPTY_KEY) {
-        return false;
-      }
-      if (k == key) {
-        return true;
-      }
-    }
-  }
-
-  private void basePut(final int key, final int value) {
-    int count = 1;
-    int index = firstProbe(key);
-    while ((keys[index] != EMPTY_KEY) && (keys[index] != key)) {
-      index = nextProbe(index, count++);
-    }
-    if (keys[index] != key) {
-      incrementSize();
-      keys[index] = key;
-    }
-    values[index] = value;
-  }
-
-  void resize() {
-    final int[] oldKeys = keys;
-    final int[] oldValues = values;
-    final int oldLength = length();
-    super.resize();
-    // Repopulate.
-    for (int index = 0; index < oldLength; index++) {
-      int key = oldKeys[index];
-      if (key != EMPTY_KEY) {
-        basePut(key, oldValues[index]);
-      }
-    }
-  }
-
-  void initialize(final int length, final int limit) {
-    super.initialize(length, limit);
-    keys = new int[length];
-    Arrays.fill(keys, EMPTY_KEY);
-    values = new int[length];
-  }
-
-
-  @SuppressWarnings("unchecked")
-  public Iterable<Integer> values() {
-    return () -> Arrays.stream(keys).filter(k -> k > EMPTY_KEY).map(this::get).iterator();
-  }
-
-  @SuppressWarnings("unchecked")
-  public Iterable<Integer> keys() {
-    return () -> Arrays.stream(keys).filter(k -> k > EMPTY_KEY).iterator();
-  }
-}
diff --git a/src/test/java/com/android/tools/r8/D8RunExamplesAndroidNTest.java b/src/test/java/com/android/tools/r8/D8RunExamplesAndroidNTest.java
new file mode 100644
index 0000000..7fb4bcf
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/D8RunExamplesAndroidNTest.java
@@ -0,0 +1,46 @@
+// Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+package com.android.tools.r8;
+
+import com.android.tools.r8.D8Command.Builder;
+import com.android.tools.r8.errors.CompilationError;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.function.UnaryOperator;
+
+public class D8RunExamplesAndroidNTest extends RunExamplesAndroidNTest<D8Command.Builder> {
+
+  class D8TestRunner extends TestRunner {
+
+    D8TestRunner(String testName, String packageName, String mainClass) {
+      super(testName, packageName, mainClass);
+    }
+
+    @Override
+    TestRunner withMinApiLevel(int minApiLevel) {
+      return withBuilderTransformation(builder -> builder.setMinApiLevel(minApiLevel));
+    }
+
+    @Override
+    void build(Path inputFile, Path out) throws Throwable {
+      D8Command.Builder builder = D8Command.builder();
+      for (UnaryOperator<Builder> transformation : builderTransformations) {
+        builder = transformation.apply(builder);
+      }
+      builder.addLibraryFiles(Paths.get(ToolHelper.getAndroidJar(builder.getMinApiLevel())));
+      D8Command command = builder.addProgramFiles(inputFile).setOutputPath(out).build();
+      try {
+        ToolHelper.runD8(command, this::combinedOptionConsumer);
+      } catch (RuntimeException re) {
+        throw re instanceof CompilationError ? re : re.getCause();
+      }
+    }
+  }
+
+  @Override
+  TestRunner test(String testName, String packageName, String mainClass) {
+    return new D8TestRunner(testName, packageName, mainClass);
+  }
+}
diff --git a/src/test/java/com/android/tools/r8/R8RunExamplesAndroidNTest.java b/src/test/java/com/android/tools/r8/R8RunExamplesAndroidNTest.java
index c4b13d9..13c38ca 100644
--- a/src/test/java/com/android/tools/r8/R8RunExamplesAndroidNTest.java
+++ b/src/test/java/com/android/tools/r8/R8RunExamplesAndroidNTest.java
@@ -4,144 +4,40 @@
 
 package com.android.tools.r8;
 
-import static com.android.tools.r8.utils.FileUtils.JAR_EXTENSION;
-import static com.android.tools.r8.utils.FileUtils.ZIP_EXTENSION;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
-
-import com.android.tools.r8.ToolHelper.DexVm;
-import com.android.tools.r8.ToolHelper.ProcessResult;
-import com.android.tools.r8.dex.Constants;
-import com.android.tools.r8.errors.CompilationError;
-import com.android.tools.r8.utils.InternalOptions;
-import com.android.tools.r8.utils.OffOrAuto;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
 import java.nio.file.Path;
-import java.nio.file.Paths;
-import java.util.List;
-import java.util.Map;
 import java.util.concurrent.ExecutionException;
-import java.util.function.Consumer;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.rules.ExpectedException;
-import org.junit.rules.TemporaryFolder;
+import java.util.function.UnaryOperator;
 
-public class R8RunExamplesAndroidNTest {
+public class R8RunExamplesAndroidNTest extends RunExamplesAndroidNTest<R8Command.Builder> {
 
-  private static final String EXAMPLE_DIR = ToolHelper.EXAMPLES_ANDROID_N_BUILD_DIR;
+  class R8TestRunner extends TestRunner {
 
-  private static Map<DexVm, List<String>> failsOn =
-      ImmutableMap.of(
-          DexVm.ART_4_4_4,
-          ImmutableList.of(),
-          DexVm.ART_5_1_1,
-          ImmutableList.of(),
-          DexVm.ART_6_0_1,
-          ImmutableList.of(),
-          DexVm.ART_7_0_0,
-          ImmutableList.of(),
-          DexVm.ART_DEFAULT,
-          ImmutableList.of());
-
-  @Rule public TemporaryFolder temp = ToolHelper.getTemporaryFolderForTest();
-
-  @Rule public ExpectedException thrown = ExpectedException.none();
-
-  @Test
-  public void staticInterfaceMethods() throws Throwable {
-    doTest(
-        "staticinterfacemethods",
-        "interfacemethods",
-        "StaticInterfaceMethods",
-        Constants.ANDROID_K_API,
-        options -> options.interfaceMethodDesugaring = OffOrAuto.Auto);
-  }
-
-  @Test
-  public void staticInterfaceMethodsErrorDueToMinSdk() throws Throwable {
-    thrown.expect(CompilationError.class);
-    doTest(
-        "staticinterfacemethods-error-due-to-min-sdk",
-        "interfacemethods",
-        "StaticInterfaceMethods");
-  }
-
-  @Test
-  public void defaultMethods() throws Throwable {
-    doTest(
-        "defaultmethods",
-        "interfacemethods",
-        "DefaultMethods",
-        Constants.ANDROID_K_API,
-        options -> options.interfaceMethodDesugaring = OffOrAuto.Auto);
-  }
-
-  @Test
-  public void defaultMethodsErrorDueToMinSdk() throws Throwable {
-    thrown.expect(CompilationError.class);
-    doTest("defaultmethods-error-due-to-min-sdk", "interfacemethods", "DefaultMethods");
-  }
-
-  private void doTest(String testName, String packageName, String className) throws Throwable {
-    doTest(testName, packageName, className, R8Command.builder(), options -> {});
-  }
-
-  private void doTest(
-      String testName,
-      String packageName,
-      String className,
-      int minSdk,
-      Consumer<InternalOptions> optionsConsumer)
-      throws Throwable {
-    doTest(
-        testName,
-        packageName,
-        className,
-        R8Command.builder().setMinApiLevel(minSdk),
-        optionsConsumer);
-  }
-
-  public void doTest(
-      String testName,
-      String packageName,
-      String className,
-      R8Command.Builder builder,
-      Consumer<InternalOptions> optionsConsumer)
-      throws Throwable {
-    String mainClass = packageName + "." + className;
-    Path inputFile = Paths.get(EXAMPLE_DIR, packageName + JAR_EXTENSION);
-    Path out = temp.getRoot().toPath().resolve(testName + ZIP_EXTENSION);
-
-    try {
-      ToolHelper.runR8(
-          builder.addProgramFiles(inputFile).setOutputPath(out).build(), optionsConsumer);
-    } catch (ExecutionException e) {
-      throw e.getCause();
+    R8TestRunner(String testName, String packageName, String mainClass) {
+      super(testName, packageName, mainClass);
     }
 
-    if (!ToolHelper.artSupported()) {
-      return;
+    @Override
+    TestRunner withMinApiLevel(int minApiLevel) {
+      return withBuilderTransformation(builder -> builder.setMinApiLevel(minApiLevel));
     }
 
-    boolean expectedToFail = false;
-    if (failsOn.containsKey(ToolHelper.getDexVm())
-        && failsOn.get(ToolHelper.getDexVm()).contains(testName)) {
-      expectedToFail = true;
-      thrown.expect(Throwable.class);
+    @Override
+    void build(Path inputFile, Path out) throws Throwable {
+      try {
+        R8Command.Builder builder = R8Command.builder();
+        for (UnaryOperator<R8Command.Builder> transformation : builderTransformations) {
+          builder = transformation.apply(builder);
+        }
+        R8Command command = builder.addProgramFiles(inputFile).setOutputPath(out).build();
+        ToolHelper.runR8(command, this::combinedOptionConsumer);
+      } catch (ExecutionException e) {
+        throw e.getCause();
+      }
     }
-    String output = ToolHelper.runArtNoVerificationErrors(out.toString(), mainClass);
-    if (!expectedToFail) {
-      ProcessResult javaResult =
-          ToolHelper.runJava(ImmutableList.of(inputFile.toString()), mainClass);
-      assertEquals("JVM run failed", javaResult.exitCode, 0);
-      assertTrue(
-          "JVM output does not match art output.\n\tjvm: "
-              + javaResult.stdout
-              + "\n\tart: "
-              + output,
-          output.equals(javaResult.stdout));
-    }
+  }
+
+  @Override
+  TestRunner test(String testName, String packageName, String mainClass) {
+    return new R8TestRunner(testName, packageName, mainClass);
   }
 }
diff --git a/src/test/java/com/android/tools/r8/R8RunSmaliTestsTest.java b/src/test/java/com/android/tools/r8/R8RunSmaliTestsTest.java
index 3fe2173..8c5e094 100644
--- a/src/test/java/com/android/tools/r8/R8RunSmaliTestsTest.java
+++ b/src/test/java/com/android/tools/r8/R8RunSmaliTestsTest.java
@@ -78,13 +78,14 @@
             "java.lang.NullPointerException: Attempt to read from field " +
                 "'Test Test.a' on a null object reference\n"},
         {"merge-blocks-regression", "java.lang.NullPointerException: Attempt to invoke virtual"
-            +" method 'Test Test.bW_()' on a null object reference\n"},
+            + " method 'Test Test.bW_()' on a null object reference\n"},
         {"self-is-catch-block", "100\n-1\n"},
         {"infinite-loop", ""},
         {"regression/33336471",
             "START\n0\n2\nLOOP\n1\n2\nLOOP\n2\n2\nDONE\n" +
                 "START\n0\n2\nLOOP\n1\n2\nLOOP\n2\n2\nDONE\n"},
         {"regression/33846227", ""},
+        {"illegal-invokes", "ICCE\nICCE\n"},
     });
   }
 
@@ -123,7 +124,8 @@
         thrown.expect(Throwable.class);
       }
       output =
-          ToolHelper.checkArtOutputIdentical(originalDexFile.toString(), generated, mainClass, null);
+          ToolHelper
+              .checkArtOutputIdentical(originalDexFile.toString(), generated, mainClass, null);
     }
     assertEquals(expectedOutput, output);
   }
diff --git a/src/test/java/com/android/tools/r8/RunExamplesAndroidNTest.java b/src/test/java/com/android/tools/r8/RunExamplesAndroidNTest.java
new file mode 100644
index 0000000..cb28cc4
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/RunExamplesAndroidNTest.java
@@ -0,0 +1,157 @@
+// Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+package com.android.tools.r8;
+
+import static com.android.tools.r8.utils.FileUtils.JAR_EXTENSION;
+import static com.android.tools.r8.utils.FileUtils.ZIP_EXTENSION;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import com.android.tools.r8.ToolHelper.DexVm;
+import com.android.tools.r8.ToolHelper.ProcessResult;
+import com.android.tools.r8.dex.Constants;
+import com.android.tools.r8.errors.CompilationError;
+import com.android.tools.r8.utils.InternalOptions;
+import com.android.tools.r8.utils.OffOrAuto;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ExecutionException;
+import java.util.function.Consumer;
+import java.util.function.UnaryOperator;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.junit.rules.TemporaryFolder;
+
+public abstract class RunExamplesAndroidNTest<B> {
+
+  private static final String EXAMPLE_DIR = ToolHelper.EXAMPLES_ANDROID_N_BUILD_DIR;
+
+  abstract class TestRunner {
+    final String testName;
+    final String packageName;
+    final String mainClass;
+
+    final List<Consumer<InternalOptions>> optionConsumers = new ArrayList<>();
+    final List<UnaryOperator<B>> builderTransformations = new ArrayList<>();
+
+    TestRunner(String testName, String packageName, String mainClass) {
+      this.testName = testName;
+      this.packageName = packageName;
+      this.mainClass = mainClass;
+    }
+
+    TestRunner withOptionConsumer(Consumer<InternalOptions> consumer) {
+      optionConsumers.add(consumer);
+      return this;
+    }
+
+    TestRunner withInterfaceMethodDesugaring(OffOrAuto behavior) {
+      return withOptionConsumer(o -> o.interfaceMethodDesugaring = behavior);
+    }
+
+    TestRunner withBuilderTransformation(UnaryOperator<B> builderTransformation) {
+      builderTransformations.add(builderTransformation);
+      return this;
+    }
+
+    void combinedOptionConsumer(InternalOptions options) {
+      for (Consumer<InternalOptions> consumer : optionConsumers) {
+        consumer.accept(options);
+      }
+    }
+
+    void run() throws Throwable {
+      String qualifiedMainClass = packageName + "." + mainClass;
+      Path inputFile = Paths.get(EXAMPLE_DIR, packageName + JAR_EXTENSION);
+      Path out = temp.getRoot().toPath().resolve(testName + ZIP_EXTENSION);
+
+      build(inputFile, out);
+
+      if (!ToolHelper.artSupported()) {
+        return;
+      }
+
+      boolean expectedToFail = false;
+      if (failsOn.containsKey(ToolHelper.getDexVm())
+          && failsOn.get(ToolHelper.getDexVm()).contains(testName)) {
+        expectedToFail = true;
+        thrown.expect(Throwable.class);
+      }
+      String output = ToolHelper.runArtNoVerificationErrors(out.toString(), qualifiedMainClass);
+      if (!expectedToFail) {
+        ProcessResult javaResult =
+            ToolHelper.runJava(ImmutableList.of(inputFile.toString()), qualifiedMainClass);
+        assertEquals("JVM run failed", javaResult.exitCode, 0);
+        assertTrue(
+            "JVM output does not match art output.\n\tjvm: "
+                + javaResult.stdout
+                + "\n\tart: "
+                + output,
+            output.equals(javaResult.stdout));
+      }
+    }
+
+    abstract TestRunner withMinApiLevel(int minApiLevel);
+
+    abstract void build(Path inputFile, Path out) throws Throwable;
+  }
+
+  private static Map<DexVm, List<String>> failsOn =
+      ImmutableMap.of(
+          DexVm.ART_4_4_4,
+          ImmutableList.of(),
+          DexVm.ART_5_1_1,
+          ImmutableList.of(),
+          DexVm.ART_6_0_1,
+          ImmutableList.of(),
+          DexVm.ART_7_0_0,
+          ImmutableList.of(),
+          DexVm.ART_DEFAULT,
+          ImmutableList.of());
+
+  @Rule public TemporaryFolder temp = ToolHelper.getTemporaryFolderForTest();
+
+  @Rule public ExpectedException thrown = ExpectedException.none();
+
+  @Test
+  public void staticInterfaceMethods() throws Throwable {
+    test("staticinterfacemethods", "interfacemethods", "StaticInterfaceMethods")
+        .withMinApiLevel(Constants.ANDROID_K_API)
+        .withInterfaceMethodDesugaring(OffOrAuto.Auto)
+        .run();
+  }
+
+  @Test
+  public void staticInterfaceMethodsErrorDueToMinSdk() throws Throwable {
+    thrown.expect(CompilationError.class);
+    test("staticinterfacemethods-error-due-to-min-sdk", "interfacemethods",
+        "StaticInterfaceMethods")
+        .run();
+  }
+
+  @Test
+  public void defaultMethods() throws Throwable {
+    test("defaultmethods", "interfacemethods", "DefaultMethods")
+        .withMinApiLevel(Constants.ANDROID_K_API)
+        .withInterfaceMethodDesugaring(OffOrAuto.Auto)
+        .run();
+  }
+
+  @Test
+  public void defaultMethodsErrorDueToMinSdk() throws Throwable {
+    thrown.expect(CompilationError.class);
+    test("defaultmethods-error-due-to-min-sdk", "interfacemethods",
+        "DefaultMethods")
+        .run();
+  }
+
+  abstract TestRunner test(String testName, String packageName, String mainClass);
+}
diff --git a/src/test/java/com/android/tools/r8/utils/HashMapIntTest.java b/src/test/java/com/android/tools/r8/utils/HashMapIntTest.java
deleted file mode 100644
index 5d8fffe..0000000
--- a/src/test/java/com/android/tools/r8/utils/HashMapIntTest.java
+++ /dev/null
@@ -1,81 +0,0 @@
-// Copyright (c) 2016, the R8 project authors. Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-package com.android.tools.r8.utils;
-
-import com.google.common.collect.ImmutableSet;
-import com.google.common.collect.Iterables;
-import java.util.Random;
-import java.util.Set;
-import org.junit.Assert;
-import org.junit.Test;
-
-public class HashMapIntTest {
-
-  static private String getString(int i) {
-    String SALTCHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
-    StringBuilder salt = new StringBuilder();
-    Random rnd = new Random();
-    while (salt.length() < 18) {
-      int index = (int) (rnd.nextFloat() * SALTCHARS.length());
-      salt.append(SALTCHARS.charAt(index));
-    }
-    salt.append(" ");
-    salt.append(i);
-    return salt.toString();
-  }
-
-  @Test(expected = RuntimeException.class)
-  public void putInvalid() throws Exception {
-    HashMapInt<Object> map = new HashMapInt<>();
-    map.put(null, 12);
-  }
-
-  @Test
-  public void put() throws Exception {
-    HashMapInt<Object> map = new HashMapInt<>();
-    Object key = new Object();
-    int value = 0;
-    map.put(key, value);
-    Assert.assertTrue(map.containsKey(key));
-    Assert.assertFalse(map.containsKey(new Object[0]));
-    Assert.assertEquals(map.get(key), value);
-    Assert.assertEquals(map.size(), 1);
-  }
-
-  @Test
-  public void random() throws Exception {
-    final int length = 5999;
-    HashMapInt<String> map = new HashMapInt<>();
-    String[] array = new String[length];
-    for (int i = 0; i < length; i++) {
-      array[i] = getString(i);
-      map.put(array[i], i * 3);
-    }
-    Assert.assertEquals(length, map.size());
-    for (int i = 0; i < length; i++) {
-      Assert.assertEquals(map.get(array[i]), i * 3);
-    }
-    for (int i : map.values()) {
-      Assert.assertTrue(i < length * 3 && i >= 0 && i % 3 == 0);
-    }
-    Assert.assertEquals(length, Iterables.size(map.values()));
-    Set<String> items = ImmutableSet.copyOf(array);
-    for (String s : map.keys()) {
-      Assert.assertTrue(items.contains(s));
-    }
-    Assert.assertEquals(length, Iterables.size(map.keys()));
-  }
-
-  @Test
-  public void overwrite() throws Exception {
-    HashMapInt<Object> map = new HashMapInt<>();
-    Object key = new Object();
-    int value1 = 0;
-    map.put(key, value1);
-    Assert.assertEquals(map.get(key), value1);
-    int value2 = -1;
-    map.put(key, value2);
-    Assert.assertEquals(map.get(key), value2);
-  }
-}
diff --git a/src/test/java/com/android/tools/r8/utils/IdentityHashMapIntTest.java b/src/test/java/com/android/tools/r8/utils/IdentityHashMapIntTest.java
deleted file mode 100644
index dd57960..0000000
--- a/src/test/java/com/android/tools/r8/utils/IdentityHashMapIntTest.java
+++ /dev/null
@@ -1,78 +0,0 @@
-// Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-package com.android.tools.r8.utils;
-
-import com.google.common.collect.Iterables;
-import com.google.common.collect.Sets;
-import java.util.Collections;
-import java.util.Set;
-import org.junit.Assert;
-import org.junit.Test;
-
-public class IdentityHashMapIntTest {
-
-  @Test(expected = RuntimeException.class)
-  public void putInvalid() throws Exception {
-    IdentityHashMapInt<Object> map = new IdentityHashMapInt<>();
-    map.put(null, 12);
-  }
-
-  @Test
-  public void put() throws Exception {
-    IdentityHashMapInt<Object> map = new IdentityHashMapInt<>();
-    Object key = new AllEqual();
-    int value = 0;
-    map.put(key, value);
-    Assert.assertTrue(map.containsKey(key));
-    Assert.assertFalse(map.containsKey(new Object()));
-    Assert.assertFalse(map.containsKey(new AllEqual()));
-    Assert.assertEquals(map.get(key), value);
-    Assert.assertEquals(map.size(), 1);
-  }
-
-  @Test
-  public void random() throws Exception {
-    final int length = 5999;
-    IdentityHashMapInt<Object> map = new IdentityHashMapInt<>();
-    AllEqual[] array = new AllEqual[length];
-    for (int i = 0; i < length; i++) {
-      array[i] = new AllEqual();
-      map.put(array[i], i * 3);
-    }
-    Assert.assertEquals(length, map.size());
-    for (int i = 0; i < length; i++) {
-      Assert.assertEquals(map.get(array[i]), i * 3);
-    }
-    for (int i : map.values()) {
-      Assert.assertTrue(i < length * 3 && i >= 0 && i % 3 == 0);
-    }
-    Assert.assertEquals(length, Iterables.size(map.values()));
-    Set<Object> items = Sets.newIdentityHashSet();
-    Collections.addAll(items, array);
-    for (Object o : map.keys()) {
-      Assert.assertTrue(items.contains(o));
-    }
-    Assert.assertEquals(length, Iterables.size(map.keys()));
-  }
-
-  @Test
-  public void overwrite() throws Exception {
-    IdentityHashMapInt<Object> map = new IdentityHashMapInt<>();
-    Object key = new Object();
-    int value1 = 0;
-    map.put(key, value1);
-    Assert.assertEquals(map.get(key), value1);
-    int value2 = -1;
-    map.put(key, value2);
-    Assert.assertEquals(map.get(key), value2);
-  }
-
-  private static class AllEqual {
-
-    @Override
-    public boolean equals(Object o) {
-      return true;
-    }
-  }
-}
diff --git a/src/test/java/com/android/tools/r8/utils/IntHashMapTest.java b/src/test/java/com/android/tools/r8/utils/IntHashMapTest.java
deleted file mode 100644
index c4b4dc2..0000000
--- a/src/test/java/com/android/tools/r8/utils/IntHashMapTest.java
+++ /dev/null
@@ -1,83 +0,0 @@
-// Copyright (c) 2016, the R8 project authors. Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-package com.android.tools.r8.utils;
-
-import com.google.common.collect.ImmutableSet;
-import com.google.common.collect.Iterables;
-import java.util.Random;
-import java.util.Set;
-import org.junit.Assert;
-import org.junit.Test;
-
-public class IntHashMapTest {
-
-  static private String getRandomString() {
-    String SALTCHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
-    StringBuilder salt = new StringBuilder();
-    Random rnd = new Random();
-    while (salt.length() < 18) {
-      int index = (int) (rnd.nextFloat() * SALTCHARS.length());
-      salt.append(SALTCHARS.charAt(index));
-    }
-    return salt.toString();
-  }
-
-  @Test(expected = RuntimeException.class)
-  public void putInvalid() throws Exception {
-    IntHashMap<Object> map = new IntHashMap<>();
-    map.put(12, null);
-  }
-
-  @Test
-  public void put() throws Exception {
-    IntHashMap<Object> map = new IntHashMap<>();
-    int key = 1;
-    Object value = new Object();
-    map.put(key, value);
-    Assert.assertEquals(map.get(key), value);
-    Assert.assertEquals(map.size(), 1);
-    map.put(key + 1, value);
-    Assert.assertEquals(map.get(key + 1), value);
-    Assert.assertEquals(map.size(), 2);
-    Assert.assertEquals(map.get(0), null);
-    map.put(0, value);
-    Assert.assertEquals(map.get(0), value);
-  }
-
-  @Test
-  public void random() throws Exception {
-    final int length = 5999;
-    IntHashMap<String> map = new IntHashMap<>();
-    String[] array = new String[length];
-    for (int i = 0; i < length; i++) {
-      array[i] = getRandomString();
-      map.put(i, array[i]);
-    }
-    Assert.assertEquals(length, map.size());
-    for (int i = 0; i < length; i++) {
-      Assert.assertEquals(map.get(i), array[i]);
-    }
-    Set<String> items = ImmutableSet.copyOf(array);
-    for (String s : map.values()) {
-      Assert.assertTrue(items.contains(s));
-    }
-    Assert.assertEquals(length, Iterables.size(map.values()));
-    for (int i : map.keys()) {
-      Assert.assertTrue(i < length && i >= 0);
-    }
-    Assert.assertEquals(length, Iterables.size(map.keys()));
-  }
-
-  @Test
-  public void overwrite() throws Exception {
-    IntHashMap<Object> map = new IntHashMap<>();
-    int key = 1;
-    Object value1 = new Object();
-    map.put(key, value1);
-    Assert.assertEquals(map.get(key), value1);
-    Object value2 = new Object[0];
-    map.put(key, value2);
-    Assert.assertEquals(map.get(key), value2);
-  }
-}
diff --git a/src/test/java/com/android/tools/r8/utils/IntIntHashMapTest.java b/src/test/java/com/android/tools/r8/utils/IntIntHashMapTest.java
deleted file mode 100644
index d129a03..0000000
--- a/src/test/java/com/android/tools/r8/utils/IntIntHashMapTest.java
+++ /dev/null
@@ -1,75 +0,0 @@
-// Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-package com.android.tools.r8.utils;
-
-import com.google.common.collect.Iterables;
-import java.util.Iterator;
-import java.util.LinkedHashSet;
-import java.util.Random;
-import java.util.Set;
-import org.junit.Assert;
-import org.junit.Test;
-
-public class IntIntHashMapTest {
-
-  @Test(expected = RuntimeException.class)
-  public void putInvalid() throws Exception {
-    IntIntHashMap map = new IntIntHashMap();
-    map.put(-1, 12);
-  }
-
-  @Test
-  public void put() throws Exception {
-    IntIntHashMap map = new IntIntHashMap();
-    int key = 22;
-    int value = 0;
-    map.put(key, value);
-    Assert.assertTrue(map.containsKey(key));
-    Assert.assertFalse(map.containsKey(33));
-    Assert.assertEquals(map.get(key), value);
-    Assert.assertEquals(map.size(), 1);
-  }
-
-  @Test
-  public void random() throws Exception {
-    final int length = 5999;
-    IntIntHashMap map = new IntIntHashMap();
-    Random rnd = new Random();
-    Set<Integer> seen = new LinkedHashSet<>();
-    String[] array = new String[length];
-    for (int i = 0; i < length; i++) {
-      int next;
-      do {
-        next = rnd.nextInt(4 * length);
-      } while (seen.contains(next));
-      seen.add(next);
-      map.put(next, i * 3);
-    }
-    Assert.assertEquals(seen.size(), map.size());
-    Iterator<Integer> it = seen.iterator();
-    for (int i = 0; i < length; i++) {
-      Assert.assertEquals(map.get(it.next()), i * 3);
-    }
-    for (int i : map.values()) {
-      Assert.assertTrue(i < length * 3 && i >= 0 && i % 3 == 0);
-    }
-    Assert.assertEquals(length, Iterables.size(map.values()));
-    for (Integer key : map.keys()) {
-      Assert.assertTrue(seen.contains(key));
-    }
-    Assert.assertEquals(seen.size(), Iterables.size(map.keys()));
-  }
-
-  @Test
-  public void overwrite() throws Exception {
-    IntIntHashMap map = new IntIntHashMap();
-    int key = 42;
-    int value1 = 0;
-    map.put(key, value1);
-    Assert.assertEquals(map.get(key), value1);
-    int value2 = -1;
-    map.put(key, value2);
-    Assert.assertEquals(map.get(key), value2);
-  }
-}
diff --git a/src/test/smali/illegal-invokes/Iface.java b/src/test/smali/illegal-invokes/Iface.java
new file mode 100644
index 0000000..dd11626
--- /dev/null
+++ b/src/test/smali/illegal-invokes/Iface.java
@@ -0,0 +1,9 @@
+// Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+public class Iface {
+
+  public void bar() {
+  }
+}
diff --git a/src/test/smali/illegal-invokes/Iface.smali b/src/test/smali/illegal-invokes/Iface.smali
new file mode 100644
index 0000000..d66777c
--- /dev/null
+++ b/src/test/smali/illegal-invokes/Iface.smali
@@ -0,0 +1,10 @@
+# Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+.class interface public LIface;
+.super Ljava/lang/Object;
+
+.method public abstract bar()V
+.end method
+
diff --git a/src/test/smali/illegal-invokes/Lowest.java b/src/test/smali/illegal-invokes/Lowest.java
new file mode 100644
index 0000000..e464313
--- /dev/null
+++ b/src/test/smali/illegal-invokes/Lowest.java
@@ -0,0 +1,11 @@
+// Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+public class Lowest extends Iface implements Super {
+
+  @Override
+  public void foo() {
+
+  }
+}
diff --git a/src/test/smali/illegal-invokes/Lowest.smali b/src/test/smali/illegal-invokes/Lowest.smali
new file mode 100644
index 0000000..d6c5787
--- /dev/null
+++ b/src/test/smali/illegal-invokes/Lowest.smali
@@ -0,0 +1,12 @@
+# Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+.class public LLowest;
+.super LSuper;
+
+.method public bar()V
+    .locals 0
+    return-void
+.end method
+
diff --git a/src/test/smali/illegal-invokes/Super.java b/src/test/smali/illegal-invokes/Super.java
new file mode 100644
index 0000000..54a8714
--- /dev/null
+++ b/src/test/smali/illegal-invokes/Super.java
@@ -0,0 +1,8 @@
+// Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+public interface Super {
+
+  public void foo();
+}
diff --git a/src/test/smali/illegal-invokes/Super.smali b/src/test/smali/illegal-invokes/Super.smali
new file mode 100644
index 0000000..1ec4f0e
--- /dev/null
+++ b/src/test/smali/illegal-invokes/Super.smali
@@ -0,0 +1,13 @@
+# Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+.class public LSuper;
+.super Ljava/lang/Object;
+.implements LIface;
+
+.method public foo()V
+    .locals 0
+    return-void
+.end method
+
diff --git a/src/test/smali/illegal-invokes/Test.java b/src/test/smali/illegal-invokes/Test.java
new file mode 100644
index 0000000..8ddd18e
--- /dev/null
+++ b/src/test/smali/illegal-invokes/Test.java
@@ -0,0 +1,30 @@
+// Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+public class Test {
+
+  int ignore;
+
+  public static void main(String... args) {
+    Lowest l = new Lowest();
+    callVirtualOnIface(l);
+    callIfaceOnVirtual(l);
+  }
+
+  private static void callVirtualOnIface(Iface i) {
+    try {
+      i.bar();
+    } catch (IncompatibleClassChangeError e) {
+      System.out.println("ICCE");
+    }
+  }
+
+  private static void callIfaceOnVirtual(Super s) {
+    try {
+      s.foo();
+    } catch (IncompatibleClassChangeError e) {
+      System.out.println("ICCE");
+    }
+  }
+}