[tf.data vectorization] Add vectorizer for `Add` op

PiperOrigin-RevId: 216424512

6 files changed, 280 insertions, 31 deletions

diff --git a/tensorflow/core/graph/graph.cc b/tensorflow/core/graph/graph.cc
index 6f068546d2..a17491d4f7 100644
--- a/tensorflow/core/graph/graph.cc
+++ b/tensorflow/core/graph/graph.cc
@@ -34,7 +34,7 @@ namespace tensorflow {
 
 const int Graph::kControlSlot = -1;
 
-class NodeProperties {
+struct NodeProperties {
  public:
   NodeProperties(const OpDef* op_def, const NodeDef& node_def,
                  const DataTypeSlice inputs, const DataTypeSlice outputs)
diff --git a/tensorflow/core/grappler/optimizers/data/vectorization/BUILD b/tensorflow/core/grappler/optimizers/data/vectorization/BUILD
index 985d6c6c3a..09018d0124 100644
--- a/tensorflow/core/grappler/optimizers/data/vectorization/BUILD
+++ b/tensorflow/core/grappler/optimizers/data/vectorization/BUILD
@@ -9,7 +9,11 @@ load("//tensorflow/core:platform/default/build_config.bzl", "tf_protos_all")
 
 VECTORIZER_DEPS = [
     ":vectorizer_registry",
+    "//tensorflow/cc:ops",
     "//tensorflow/core/grappler/optimizers/data:graph_utils",
+    "//tensorflow/core:core_cpu",
+    "//tensorflow/cc:scope_internal",
+    "//tensorflow/cc:cc_ops",
 ] + tf_protos_all()
 
 cc_library(
@@ -42,6 +46,24 @@ cc_library(
     ],
 )
 
+tf_cc_test(
+    name = "vectorizer_registry_test",
+    srcs = ["vectorizer_registry_test.cc"],
+    deps = [
+        ":vectorizer_registry",
+        "//tensorflow/core:test",
+        "//tensorflow/core:test_main",
+        "//tensorflow/core:testlib",
+    ] + tf_protos_all(),
+)
+
+cc_library(
+    name = "add_vectorizer",
+    srcs = ["add_vectorizer.cc"],
+    deps = VECTORIZER_DEPS,
+    alwayslink = 1,
+)
+
 cc_library(
     name = "cast_vectorizer",
     srcs = ["cast_vectorizer.cc"],
@@ -61,20 +83,10 @@ cc_library(
     hdrs = ["vectorizer_registry.h"],
     visibility = ["//visibility:public"],
     deps = [
+        ":add_vectorizer",
         ":cast_vectorizer",
         ":unpack_vectorizer",
         ":vectorizer",
         ":vectorizer_registry",
     ],
 )
-
-tf_cc_test(
-    name = "vectorizer_registry_test",
-    srcs = ["vectorizer_registry_test.cc"],
-    deps = [
-        ":vectorizer_registry",
-        "//tensorflow/core:test",
-        "//tensorflow/core:test_main",
-        "//tensorflow/core:testlib",
-    ] + tf_protos_all(),
-)
diff --git a/tensorflow/core/grappler/optimizers/data/vectorization/add_vectorizer.cc b/tensorflow/core/grappler/optimizers/data/vectorization/add_vectorizer.cc
new file mode 100644
index 0000000000..d90a51b01a
--- /dev/null
+++ b/tensorflow/core/grappler/optimizers/data/vectorization/add_vectorizer.cc
@@ -0,0 +1,150 @@
+/* Copyright 2018 The TensorFlow Authors. All Rights Reserved.
+
+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 "tensorflow/cc/framework/ops.h"
+#include "tensorflow/cc/framework/scope_internal.h"
+#include "tensorflow/cc/ops/array_ops.h"
+#include "tensorflow/cc/ops/math_ops.h"
+#include "tensorflow/cc/ops/standard_ops.h"
+#include "tensorflow/core/graph/node_builder.h"
+#include "tensorflow/core/grappler/optimizers/data/vectorization/vectorizer_registry.h"
+
+namespace tensorflow {
+namespace grappler {
+
+namespace {
+
+const char* const kExpandDimsPrefix = "vectorized/expanddims/";
+
+// Reshapes stacked inputs for broadcast. Stacked inputs have an extra leading
+// dimension, which may cause automatic broadcasting rules to expand the
+// input dimensions wrongly when the unstacked shapes have different ranks.
+// To avoid that, we reshape stacked inputs to the maximum rank they need
+// to be broadcasted to.
+//
+// For example, suppose we have inputs A and B, where A is a stacked tensor with
+// shape [n, 5] (where n is the stack size) and B is an unstacked tensor with
+// shape [12, 7, 5]. If we added them directly, tensorflow broadcasting rules
+// would expand the dimensions of A to [1, n, 5], then (incorrectly) check that
+// the dimensions n and 7 are compatible, and if so, create an output of shape
+// [12, 7, 5]. However, correct addition of these inputs would create an output
+// with shape [n, 12, 7, 5]: we need to manually expand the dimensions of A
+// *after* the leading dimension, i.e. expand A to the shape [n, 1, 1, 5] before
+// broadcasting.
+Status ExpandDimsForBroadcast(std::vector<WrappedTensor>* inputs, Graph* g) {
+  Status status;
+  Scope parent = NewInternalScope(g, &status, nullptr);
+  Scope s = parent.NewSubScope(kExpandDimsPrefix);
+
+  // TODO(rachelim): We can potentially get rid of all these ops if shapes are
+  // known statically
+
+  Output const_0 = ops::Const(s, 0);
+  Output const_1 = ops::Const(s, 1);
+
+  std::vector<Output> ranks;
+  ranks.reserve(inputs->size());
+
+  // Get the stacked rank of each input
+  for (const auto& input : *inputs) {
+    Output rank = ops::Rank(s, Output(input.node, input.output_index));
+
+    if (!input.stacked) {
+      // If the input is unstacked, add 1
+      rank = ops::Add(s, rank, const_1);
+    }
+
+    ranks.push_back(rank);
+  }
+
+  // Pack the ranks into one tensor to get the max
+  Output packed_ranks = ops::Stack(s, ranks);
+
+  Output max_rank =
+      ops::Max(s, packed_ranks, const_0, ops::Max::Attrs().KeepDims(true));
+
+  std::vector<WrappedTensor> expanded_inputs;
+  expanded_inputs.reserve(inputs->size());
+
+  // For all inputs that are stacked, expand dimensions after dim 0.
+  for (size_t i = 0; i < inputs->size(); ++i) {
+    if (!inputs->at(i).stacked) {
+      expanded_inputs.push_back(inputs->at(i));
+      continue;
+    }
+
+    Output input(inputs->at(i).node, inputs->at(i).output_index);
+
+    // Number of dimensions to expand
+    Output rank_diff = ops::Sub(s, max_rank, ranks[i]);
+
+    // [1] * rank_diff
+    Output ones = ops::Tile(s, ops::Const(s, {1}), rank_diff);
+
+    Output const_vec_1 = ops::Const(s, {1});
+
+    Output shape = ops::Shape(s, input);
+
+    // shape[:1]
+    Output concat_pre =
+        ops::StridedSlice(s, shape, const_vec_1, const_vec_1, const_vec_1,
+                          ops::StridedSlice::Attrs().BeginMask(1));
+
+    // shape[1:]
+    Output concat_post =
+        ops::StridedSlice(s, shape, const_vec_1, const_vec_1, const_vec_1,
+                          ops::StridedSlice::Attrs().EndMask(1));
+
+    // tf.concat([shape[:1], ones, shape[1:]], 0)
+    Output new_shape = ops::Concat(s, {concat_pre, ones, concat_post}, const_0);
+
+    Output result = ops::Reshape(s, input, new_shape);
+
+    expanded_inputs.push_back({result.node(), 0, true});
+  }
+
+  inputs->swap(expanded_inputs);
+  return status;
+}
+
+class AddVectorizer : public Vectorizer {
+ public:
+  Status Vectorize(const Node& node, Graph* outer_scope,
+                   std::vector<WrappedTensor>&& inputs,
+                   std::vector<WrappedTensor>* outputs) override {
+    if (node.num_inputs() != 2) {
+      return errors::Internal("Add op should only have two inputs.");
+    }
+
+    TF_RETURN_IF_ERROR(ExpandDimsForBroadcast(&inputs, outer_scope));
+
+    // Add new Add node with the same op and attrs as the original node
+    Node* new_add_node;
+    TF_RETURN_IF_ERROR(NodeBuilder("Add", "Add")
+                           .Input(inputs[0].node, inputs[0].output_index)
+                           .Input(inputs[1].node, inputs[1].output_index)
+                           .Finalize(outer_scope, &new_add_node));
+
+    // Add output mappings
+    outputs->push_back({new_add_node, 0, true});
+    return Status::OK();
+  }
+};
+
+REGISTER_VECTORIZER("Add", AddVectorizer);
+
+}  // namespace
+}  // namespace grappler
+}  // namespace tensorflow
diff --git a/tensorflow/core/grappler/optimizers/data/vectorization_utils.cc b/tensorflow/core/grappler/optimizers/data/vectorization_utils.cc
index d977ff3198..8b93b1f2b8 100644
--- a/tensorflow/core/grappler/optimizers/data/vectorization_utils.cc
+++ b/tensorflow/core/grappler/optimizers/data/vectorization_utils.cc
@@ -64,9 +64,18 @@ void ReplaceEdgeSources(const TensorDesc& old_src, const TensorDesc& new_src,
   }
 }
 
+// Update node attrs to keep its properties consistent with the function
+void UpdateMapDefunAttrs(FunctionBody* map_defun_fn, Node* map_defun_node) {
+  map_defun_node->AddAttr("output_types", map_defun_fn->ret_types);
+
+  // TODO(rachelim): Propagate precise shapes if they're known, which may enable
+  // subsequent optimizations.
+  map_defun_node->AddAttr("output_shapes", std::vector<PartialTensorShape>(
+                                               map_defun_fn->ret_types.size()));
+}
+
 Status AddMapDefunOutput(FunctionBody* map_defun_fn, Node* map_defun_node,
                          const TensorDesc& output) {
-  // Note that we don't update MapDefun attrs as we go, only when we are done
   DataType type = output.first->output_type(output.second);
   int index = map_defun_fn->ret_nodes.size();
 
@@ -83,13 +92,13 @@ Status AddMapDefunOutput(FunctionBody* map_defun_fn, Node* map_defun_node,
   map_defun_fn->graph->AddEdge(output.first, output.second, ret_node, 0);
   map_defun_fn->ret_nodes.push_back(ret_node);
   map_defun_fn->ret_types.push_back(type);
+  UpdateMapDefunAttrs(map_defun_fn, map_defun_node);
 
   return s;
 }
 
 void RemoveMapDefunOutput(int output_position, Graph* outer_scope,
                           FunctionBody* map_defun_fn, Node* map_defun_node) {
-  // Note that we don't update MapDefun attrs as we go, only when we are done
   DCHECK_LT(output_position, map_defun_fn->ret_nodes.size())
       << "Trying to remove output that doesn't exist. Output number: "
       << output_position;
@@ -102,6 +111,7 @@ void RemoveMapDefunOutput(int output_position, Graph* outer_scope,
                                 output_position);
   map_defun_fn->ret_types.erase(map_defun_fn->ret_types.begin() +
                                 output_position);
+  UpdateMapDefunAttrs(map_defun_fn, map_defun_node);
 
   // Renumber the nodes and edges that come after
   for (int i = 0; i < num_later_outputs; ++i) {
@@ -342,13 +352,6 @@ void Vectorization::VectorizeHelper() {
   // need the MapDefun node and can delete it.
   if (map_defun_fn_->ret_nodes.empty()) {
     outer_scope_->RemoveNode(map_defun_node_);
-  } else {
-    // Update MapDefun node attrs accordingly
-    DCHECK_EQ(map_defun_fn_->ret_types.size(), map_defun_fn_->ret_nodes.size());
-    map_defun_node_->AddAttr(
-        "output_shapes",
-        std::vector<PartialTensorShape>(map_defun_fn_->ret_types.size()));
-    map_defun_node_->AddAttr("output_types", map_defun_fn_->ret_types);
   }
 }
 
diff --git a/tensorflow/core/grappler/optimizers/data/vectorization_utils_test.cc b/tensorflow/core/grappler/optimizers/data/vectorization_utils_test.cc
index a6020e36bb..be498d150b 100644
--- a/tensorflow/core/grappler/optimizers/data/vectorization_utils_test.cc
+++ b/tensorflow/core/grappler/optimizers/data/vectorization_utils_test.cc
@@ -145,7 +145,7 @@ TEST(VectorizeMapDefunTest, VectorizeDefunNoOps) {
   FunctionDef* vectorized;
   Status s = VectorizeMapDefun(outer, *map_defun, &lib, &vectorized);
   LOG(ERROR) << s;
-  EXPECT_TRUE(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized).ok());
+  TF_EXPECT_OK(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized));
   EXPECT_TRUE(
       !function_utils::ContainsFunctionNodeWithOp("MapDefun", *vectorized));
   EXPECT_EQ(GetRetval(*vectorized, 0), "ret0");
@@ -237,7 +237,7 @@ TEST(VectorizeMapDefunTest, VectorizeDefunUnconvertible) {
   *lib.add_function() = outer;
   *lib.add_function() = inner;
   FunctionDef* vectorized;
-  EXPECT_TRUE(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized).ok());
+  TF_EXPECT_OK(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized));
 
   auto map_defun_node = vectorized->node_def(
       function_utils::FindFunctionNodeWithOp("MapDefun", *vectorized));
@@ -311,7 +311,7 @@ TEST(VectorizeMapDefunTest, VectorizeDefunSimpleCast) {
   *lib.add_function() = outer;
   *lib.add_function() = inner;
   FunctionDef* vectorized;
-  EXPECT_TRUE(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized).ok());
+  TF_EXPECT_OK(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized));
   EXPECT_TRUE(
       !function_utils::ContainsFunctionNodeWithOp("MapDefun", *vectorized));
   const NodeDef& cast_node = vectorized->node_def(
@@ -389,7 +389,7 @@ TEST(VectorizeMapDefunTest, VectorizeDefunCastUsedTwice) {
   *lib.add_function() = outer;
   *lib.add_function() = inner;
   FunctionDef* vectorized;
-  EXPECT_TRUE(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized).ok());
+  TF_EXPECT_OK(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized));
   EXPECT_TRUE(
       !function_utils::ContainsFunctionNodeWithOp("MapDefun", *vectorized));
   const NodeDef& cast_node = vectorized->node_def(
@@ -475,7 +475,7 @@ TEST(VectorizeMapDefunTest, VectorizeDefunOpWithMultipleOutputs) {
   *lib.add_function() = outer;
   *lib.add_function() = inner;
   FunctionDef* vectorized;
-  EXPECT_TRUE(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized).ok());
+  TF_EXPECT_OK(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized));
   EXPECT_TRUE(
       !function_utils::ContainsFunctionNodeWithOp("MapDefun", *vectorized));
   const NodeDef& unpack_node = vectorized->node_def(
@@ -574,7 +574,7 @@ TEST(VectorizeMapDefunTest, VectorizeDefunChainedConvertibleOps) {
   *lib.add_function() = outer;
   *lib.add_function() = inner;
   FunctionDef* vectorized;
-  EXPECT_TRUE(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized).ok());
+  TF_EXPECT_OK(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized));
   EXPECT_TRUE(
       !function_utils::ContainsFunctionNodeWithOp("MapDefun", *vectorized));
   const NodeDef& cast_node = vectorized->node_def(
@@ -654,7 +654,7 @@ TEST(VectorizeMapDefunTest, VectorizeDefunWithControlInputs) {
   *lib.add_function() = outer;
   *lib.add_function() = inner;
   FunctionDef* vectorized;
-  EXPECT_TRUE(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized).ok());
+  TF_EXPECT_OK(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized));
   // They should be unchanged
   // We check this somewhat manually as the names of nodes may have changed
   EXPECT_EQ(vectorized->node_def_size(), 1);
@@ -738,7 +738,7 @@ TEST(VectorizeMapDefunTest, VectorizeConst) {
   *lib.add_function() = outer;
   *lib.add_function() = inner;
   FunctionDef* vectorized;
-  EXPECT_TRUE(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized).ok());
+  TF_EXPECT_OK(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized));
   EXPECT_TRUE(
       !function_utils::ContainsFunctionNodeWithOp("MapDefun", *vectorized));
   EXPECT_TRUE(function_utils::ContainsFunctionNodeWithOp("Const", *vectorized));
@@ -817,7 +817,7 @@ TEST(VectorizeMapDefunTest, VectorizeUnstackedOutput) {
   *lib.add_function() = outer;
   *lib.add_function() = inner;
   FunctionDef* vectorized;
-  EXPECT_TRUE(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized).ok());
+  TF_EXPECT_OK(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized));
   EXPECT_TRUE(
       !function_utils::ContainsFunctionNodeWithOp("MapDefun", *vectorized));
   auto const_node = vectorized->node_def(
@@ -902,7 +902,7 @@ TEST(VectorizeMapDefunTest, VectorizeUnstackedControl) {
   *lib.add_function() = inner;
 
   FunctionDef* vectorized;
-  EXPECT_TRUE(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized).ok());
+  TF_EXPECT_OK(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized));
 
   auto find_const = [vectorized](int val) -> const NodeDef* {
     for (const auto& n : vectorized->node_def()) {
@@ -924,6 +924,89 @@ TEST(VectorizeMapDefunTest, VectorizeUnstackedControl) {
   EXPECT_EQ(cast_node.input(1), strings::StrCat("^", const_dep_node->name()));
 }
 
+// Before:
+//
+//                   +------+
+// +-----------------+ Arg0 +----------------------+
+// |                 +---+--+                      |
+// |                     |                         |
+// |                 +---v--+                      |
+// |   +-------------+ Arg0 +------------------+   |
+// |   |             +---+--+                  |   |
+// |   |                 |                     |   |
+// |   |                 |          +-----+    |   |
+// |   |                 |          |Const|    |   |
+// |   |                 |          +-+---+    |   |
+// |   |                 |            |        |   |
+// |   |                 |   +--------+        |   |
+// |   |                 |   |                 |   |
+// |   |               +-v---v-+               |   |
+// |   |               |  Add  |               |   |
+// |   |               +-+-----+               |   |
+// |   |                 |                     |   |
+// |   |                 |                     |   |
+// |   | MapDefun      +-v----+                |   |
+// |   +---------------| Ret  |----------------+   |
+// |                   +--v---+                    |
+// |                      |                        |
+// |                      |                        |
+// |                   +--v----                    |
+// +-------------------| Ret  |--------------------+
+//                     +------+
+//
+//
+//  After:
+//
+//              +------+
+// +------------+ Arg0 +----------------------+
+// |            +---+--+                      |
+// |                |                         |
+// |                |              +-----+    |
+// |                |              |Const|    |
+// |              +-v---------+    +--+--+    |
+// |              |ExpandDims*|       |       |
+// |              +-----+-----+       |       |
+// |                    |             |       |
+// |                    +-----+ +-----+       |
+// |                          | |             |
+// |                        +-v-v-+           |
+// |                        | Add |           |
+// |                        +--+--+           |
+// |                           |              |
+// |                       +---v--+           |
+// +-----------------------+ Ret  +-----------+
+//                         +------+
+//
+TEST(VectorizeMapDefunTest, VectorizeDefunAdd) {
+  // Note that this checks that the "Add" vectorizer is successful, but does not
+  // check that the transformed function is correct (i.e. produces the same
+  // output as the unvectorized map defun). For the latter, the tests are in
+  // tensorflow/python/data/experimental/kernel_tests/optimization/
+  // map_vectorization_test.py
+  FunctionDef inner = FunctionDefHelper::Create(
+      "inner_function", {"arg0: int32"}, {"ret0: int32"}, {/* attrs */},
+      {/* nodes */ FunctionDefHelper::Const("Const", 2),
+       {{"Add"}, "Add", {"arg0", "Const:output:0"}, {{"T", DT_INT32}}}},
+      {{"ret0", "Add:z:0"}});
+
+  FunctionDef outer = FunctionDefHelper::Create(
+      "outer_function", {"outer_arg0: int32"}, {"mapdefun: int32"},
+      {/* attrs */}, {/* nodes */}, {{"mapdefun", "MapDefun:output:0"}});
+
+  NodeDef* map_defun =
+      AddMapDefunNode("MapDefun", {"outer_arg0"}, {DT_INT32}, {DT_INT32}, {{}},
+                      inner.signature().name(), &outer);
+  CHECK_NOTNULL(map_defun);
+
+  FunctionDefLibrary lib;
+  *lib.add_function() = outer;
+  *lib.add_function() = inner;
+  FunctionDef* vectorized;
+  TF_EXPECT_OK(VectorizeMapDefun(outer, *map_defun, &lib, &vectorized));
+  EXPECT_TRUE(
+      !function_utils::ContainsFunctionNodeWithOp("MapDefun", *vectorized));
+}
+
 // TODO(rachelim): More test cases when we get around to implementing them:
 // [] A badly defined converter, e.g. doesn't produce nodes that have the
 //    same number of outputs/inputs as the nodes to be converted
diff --git a/tensorflow/python/data/experimental/kernel_tests/optimization/map_vectorization_test.py b/tensorflow/python/data/experimental/kernel_tests/optimization/map_vectorization_test.py
index 803ff87924..d1d6cf28ab 100644
--- a/tensorflow/python/data/experimental/kernel_tests/optimization/map_vectorization_test.py
+++ b/tensorflow/python/data/experimental/kernel_tests/optimization/map_vectorization_test.py
@@ -80,6 +80,7 @@ class MapVectorizationTest(test_base.DatasetTestBase, parameterized.TestCase):
       ("Basic", lambda x: (x, x + 1), None),
       ("Const", lambda x: 2, 12),
       ("Parallel", lambda x: (x, x + 1), 12),
+      ("Broadcast", lambda x: x + np.random.rand(5, 4, 3, 2), None),
       ("Gather", lambda x: array_ops.gather(x, 0), 12),
   )
   def testOptimization(self, map_fn, num_parallel_calls):