Reduce overhead of ExecutorState::ProcessOutputs:

- Cache result of LogMemory::IsEnabled.
- Init Tensor for logging only if logging is enabled.
- Add move constructor to Tensor and use it in ProcessOutputs.

Also added benchmark for copy vs move in tensor_test.cc
Change: 121487202

1 files changed, 28 insertions, 0 deletions

diff --git a/tensorflow/core/framework/tensor_shape.h b/tensorflow/core/framework/tensor_shape.h
index 84947e308a..7cc8223016 100644
--- a/tensorflow/core/framework/tensor_shape.h
+++ b/tensorflow/core/framework/tensor_shape.h
@@ -54,6 +54,13 @@ class TensorShape {
   TensorShape(const TensorShape& b);
   void operator=(const TensorShape& b);
 
+  /// Move the specified shape.  After moving, <b> is safe for destruction and
+  // can be reassigned into, but its dimensions and number of elements can be
+  // nonsensical (e.g., negative dimension sizes, or number of elements not
+  // properly recomputed).
+  TensorShape(TensorShape&& b);
+  void operator=(TensorShape&& b);
+
   /// Returns `true` iff `proto` is a valid tensor shape.
   static bool IsValid(const TensorShapeProto& proto);
 
@@ -308,6 +315,15 @@ inline TensorShape::TensorShape(const TensorShape& b) {
   }
 }
 
+inline TensorShape::TensorShape(TensorShape&& b) {
+  num_elements_ = b.num_elements_;
+  memcpy(buf(), b.buf(), sizeof(u_.buf));
+  // memcpy above Implicitly does:
+  //   set_ndims_byte(b.ndims_byte());
+  //   set_tag(b.tag());
+  b.set_tag(REP16);  // other shape no longer owns out-of-line data, if any.
+}
+
 inline TensorShape::~TensorShape() {
   if (tag() == REP_OUT_OF_LINE) {
     DestructorOutOfLine();
@@ -326,6 +342,18 @@ inline void TensorShape::operator=(const TensorShape& b) {
   }
 }
 
+inline void TensorShape::operator=(TensorShape&& b) {
+  if (tag() == REP_OUT_OF_LINE) {
+    DestructorOutOfLine();
+  }
+  num_elements_ = b.num_elements_;
+  memcpy(buf(), b.buf(), sizeof(u_.buf));
+  // memcpy above Implicitly does:
+  //   set_ndims_byte(b.ndims_byte());
+  //   set_tag(b.tag());
+  b.set_tag(REP16);  // other shape no longer owns out-of-line data, if any.
+}
+
 }  // namespace tensorflow
 
 #endif  // TENSORFLOW_CORE_FRAMEWORK_TENSOR_SHAPE_H_