diff --git a/tools/split-select/Grouper.cpp b/tools/split-select/Grouper.cpp
new file mode 100644
index 0000000..15edf89
--- /dev/null
+++ b/tools/split-select/Grouper.cpp
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "Grouper.h"
+
+#include "SplitDescription.h"
+
+#include <utils/KeyedVector.h>
+#include <utils/Vector.h>
+
+using namespace android;
+
+namespace split {
+
+template <typename Key, typename Value>
+static void addToVector(KeyedVector<Key, SortedVector<Value> >& group,
+        const Key& key, const Value& value) {
+    ssize_t idx = group.indexOfKey(key);
+    if (idx < 0) {
+        idx = group.add(key, SortedVector<Value>());
+    }
+    group.editValueAt(idx).add(value);
+}
+
+Vector<SortedVector<SplitDescription> >
+groupByMutualExclusivity(const Vector<SplitDescription>& splits) {
+    Vector<SortedVector<SplitDescription> > groups;
+
+    // Find mutually exclusive splits and group them.
+    KeyedVector<SplitDescription, SortedVector<SplitDescription> > densityGroups;
+    KeyedVector<SplitDescription, SortedVector<SplitDescription> > abiGroups;
+    KeyedVector<SplitDescription, SortedVector<SplitDescription> > localeGroups;
+    for (const SplitDescription& split : splits) {
+        if (split.config.density != 0) {
+            SplitDescription key(split);
+            key.config.density = 0;
+            key.config.sdkVersion = 0; // Ignore density so we can support anydpi.
+            addToVector(densityGroups, key, split);
+        } else if (split.abi != abi::Variant::none) {
+            SplitDescription key(split);
+            key.abi = abi::Variant::none;
+            addToVector(abiGroups, key, split);
+        } else if (split.config.locale != 0) {
+            SplitDescription key(split);
+            key.config.clearLocale();
+            addToVector(localeGroups, key, split);
+        } else {
+            groups.add();
+            groups.editTop().add(split);
+        }
+    }
+
+    const size_t densityCount = densityGroups.size();
+    for (size_t i = 0; i < densityCount; i++) {
+        groups.add(densityGroups[i]);
+    }
+
+    const size_t abiCount = abiGroups.size();
+    for (size_t i = 0; i < abiCount; i++) {
+        groups.add(abiGroups[i]);
+    }
+
+    const size_t localeCount = localeGroups.size();
+    for (size_t i = 0; i < localeCount; i++) {
+        groups.add(localeGroups[i]);
+    }
+    return groups;
+}
+
+} // namespace split