Add lowering from tf.RiscAdd op to HLO_Add.

PiperOrigin-RevId: 346663526
Change-Id: If21a1a88d27bb8c16e5a1a2331fc436646a94ee6

tensorflow/compiler/mlir/tensorflow/ir/tf_generated_ops.td

@@ -11645,6 +11645,29 @@ rint([-1.7, -1.5, -0.2, 0.2, 1.5, 1.7, 2.0]) ==> [-2., -2., -0., 0., 2., 2., 2.]
   TF_DerivedOperandTypeAttr T = TF_DerivedOperandTypeAttr<0>;
 }
 
+def TF_RiscAddOp : TF_Op<"RiscAdd", [Commutative, NoSideEffect]> {
+  let summary = "Returns x + y element-wise.";
+
+  let description = [{
+*NOTE*: `RiscAdd` does not supports broadcasting.
+
+Given two input tensors, the `tf.risc_add` operation computes the sum for every element in the tensor.
+
+Both input and output have a range `(-inf, inf)`.
+  }];
+
+  let arguments = (ins
+    TF_FloatTensor:$x,
+    TF_FloatTensor:$y
+  );
+
+  let results = (outs
+    TF_FloatTensor:$z
+  );
+
+  TF_DerivedOperandTypeAttr T = TF_DerivedOperandTypeAttr<0>;
+}
+
 def TF_RollOp : TF_Op<"Roll", [NoSideEffect]> {
   let summary = "Rolls the elements of a tensor along an axis.";
 

tensorflow/compiler/mlir/xla/transforms/legalize_tf_patterns.td

@@ -188,6 +188,8 @@ def : Pat<(TF_FloorModOp AnyTensor:$l, AnyTensor:$r),
        (HLOClient_BroadcastAddOp $r,
         $rem, (BinBroadcastDimensions $r, $rem)), $rem)>;
 
+def : Pat<(TF_RiscAddOp $l, $r), (HLO_AddOp $l, $r)>;
+
 //===----------------------------------------------------------------------===//
 // Logical & bitwise binary op patterns.
 //===----------------------------------------------------------------------===//

tensorflow/compiler/tests/BUILD

@@ -1965,3 +1965,19 @@ tf_xla_py_test(
         "//tensorflow/python/compiler/xla:compiler_py",
     ],
 )
+
+tf_xla_py_test(
+    name = "risc_ops_test",
+    size = "small",
+    srcs = ["risc_ops_test.py"],
+    enabled_backends = ["cpu"],
+    python_version = "PY3",
+    deps = [
+        ":xla_test",
+        "//tensorflow/python:framework",
+        "//tensorflow/python:is_mlir_bridge_test_true",
+        "//tensorflow/python:platform_test",
+        "//tensorflow/python/eager:function",
+        "//tensorflow/python/ops/risc:risc_ops",
+    ],
+)

tensorflow/compiler/tests/risc_ops_test.py

@@ -0,0 +1,44 @@
+# Copyright 2020 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.
+# ==============================================================================
+"""Tests for RISC Ops."""
+
+from tensorflow.compiler.tests import xla_test
+from tensorflow.python.eager import def_function
+from tensorflow.python.framework import constant_op
+from tensorflow.python.framework import dtypes
+from tensorflow.python.framework import ops
+from tensorflow.python.ops.risc import risc_ops
+from tensorflow.python.platform import test
+
+
+class XlaRiscOpsTest(xla_test.XLATestCase):
+
+  def testRiscAddBasic(self):
+
+    @def_function.function(jit_compile=True)
+    def f(a, b):
+      return risc_ops.risc_add(a, b)
+
+    l1 = constant_op.constant([[1.0, 2.0], [3.0, 4.0], [5.0, 6.0]],
+                              dtype=dtypes.float32)
+    l2 = constant_op.constant([[7.0, 8.0], [9.0, 10.0], [11.0, 12.0]],
+                              dtype=dtypes.float32)
+    l = f(l1, l2)
+    self.assertAllEqual(l, [[8.0, 10.0], [12.0, 14.0], [16.0, 18.0]])
+
+
+if __name__ == "__main__":
+  ops.enable_eager_execution()
+  test.main()

tensorflow/python/ops/risc/risc_ops.py

@@ -21,11 +21,6 @@ from __future__ import print_function
 
 from tensorflow.python.ops import gen_risc_ops
 
-# go/tf-wildcard-import
-# pylint: disable=wildcard-import
-from tensorflow.python.ops.risc_ops_gen import *
-# pylint: enable=wildcard-import
-
 
 def risc_add(
     input_lhs,