Refactoring: Extract CombineHashes function into a shared module

PiperOrigin-RevId: 198793295

4 files changed, 19 insertions, 18 deletions

diff --git a/tensorflow/contrib/lite/op_resolver.h b/tensorflow/contrib/lite/op_resolver.h
index 38a2706942..9d7e3f2085 100644
--- a/tensorflow/contrib/lite/op_resolver.h
+++ b/tensorflow/contrib/lite/op_resolver.h
@@ -18,6 +18,7 @@ limitations under the License.
 #include <unordered_map>
 #include "tensorflow/contrib/lite/context.h"
 #include "tensorflow/contrib/lite/schema/schema_generated.h"
+#include "tensorflow/contrib/lite/util.h"
 
 namespace tflite {
 
@@ -55,8 +56,7 @@ struct OperatorKeyHasher {
   size_t operator()(const T& x) const {
     size_t a = ValueHasher<typename T::first_type>()(x.first);
     size_t b = ValueHasher<typename T::second_type>()(x.second);
-    // Hash combinator used by TensorFlow core.
-    return a ^ (b + 0x9e3779b97f4a7800ULL + (a << 10) + (a >> 4));
+    return CombineHashes({a, b});
   }
 };
 }  // namespace op_resolver_hasher
diff --git a/tensorflow/contrib/lite/toco/tflite/export.h b/tensorflow/contrib/lite/toco/tflite/export.h
index 90abfb94d8..098d2163e6 100644
--- a/tensorflow/contrib/lite/toco/tflite/export.h
+++ b/tensorflow/contrib/lite/toco/tflite/export.h
@@ -17,6 +17,7 @@ limitations under the License.
 
 #include "tensorflow/contrib/lite/toco/model.h"
 #include "tensorflow/contrib/lite/toco/tflite/operator.h"
+#include "tensorflow/contrib/lite/util.h"
 
 namespace toco {
 
@@ -72,22 +73,10 @@ struct OperatorKey {
 
   struct Hash {
     size_t operator()(const OperatorKey& key) const {
-      return CombineHashes({std::hash<size_t>()(static_cast<size_t>(key.type)),
-                            std::hash<std::string>()(key.custom_code),
-                            std::hash<int>()(key.version)});
-    }
-
-   private:
-    // TODO(ycling): Refactoring and extract this function into a common
-    // utility module.
-    static size_t CombineHashes(std::initializer_list<size_t> hashes) {
-      size_t result = 0;
-      // Hash combiner used by TensorFlow core.
-      for (size_t hash : hashes) {
-        result = result ^ (hash + 0x9e3779b97f4a7800ULL + (result << 10) +
-                           (result >> 4));
-      }
-      return result;
+      return ::tflite::CombineHashes(
+          {std::hash<size_t>()(static_cast<size_t>(key.type)),
+           std::hash<std::string>()(key.custom_code),
+           std::hash<int>()(key.version)});
     }
   };
 };
diff --git a/tensorflow/contrib/lite/util.cc b/tensorflow/contrib/lite/util.cc
index fb4af07d06..8ccb65c24f 100644
--- a/tensorflow/contrib/lite/util.cc
+++ b/tensorflow/contrib/lite/util.cc
@@ -38,4 +38,14 @@ bool EqualArrayAndTfLiteIntArray(const TfLiteIntArray* a, const int b_size,
   return true;
 }
 
+size_t CombineHashes(std::initializer_list<size_t> hashes) {
+  size_t result = 0;
+  // Hash combiner used by TensorFlow core.
+  for (size_t hash : hashes) {
+    result = result ^
+             (hash + 0x9e3779b97f4a7800ULL + (result << 10) + (result >> 4));
+  }
+  return result;
+}
+
 }  // namespace tflite
diff --git a/tensorflow/contrib/lite/util.h b/tensorflow/contrib/lite/util.h
index a34db35823..89d9b4f5cf 100644
--- a/tensorflow/contrib/lite/util.h
+++ b/tensorflow/contrib/lite/util.h
@@ -35,6 +35,8 @@ TfLiteIntArray* ConvertArrayToTfLiteIntArray(const int rank, const int* dims);
 bool EqualArrayAndTfLiteIntArray(const TfLiteIntArray* a, const int b_size,
                                  const int* b);
 
+size_t CombineHashes(std::initializer_list<size_t> hashes);
+
 }  // namespace tflite
 
 #endif  // TENSORFLOW_CONTRIB_LITE_UTIL_H_