Op documentation update.

update of g3doc/tf_ops.md
	update of g3doc/includes/tf_passes.md

PiperOrigin-RevId: 350751493
Change-Id: I5ac05779c4ab944dde241e9d25991c47d42092fd

tensorflow/compiler/mlir/g3doc/includes/tf_passes.md

@@ -1,4 +1,44 @@
 <!-- Autogenerated by mlir-tblgen; don't manually edit -->
+### `-cluster-ops-by-policy`: Clusters ops according to specified policy.
+This pass clusters ops according to the policy specified by the pass options.
+Clustered ops are moved to a tf_device::clusterOp region.
+
+The only currently supported option is 'oplist=<list of ops>'. This option
+specifies the names of the ops that should be clustered if they form
+a single use def-use chain, that is, the next op in the list uses the result
+of the previous op and is the only user of that result. The ops should
+be located in the same block, be assigned to the same device and have no
+side effects.
+
+For example, running this pass with option oplist="tf.Cast, tf.Add" on:
+
+```mlir
+func @cluster_oplist(%arg0 : tensor<f32>, %arg1 : tensor<i32>) -> tensor<i32> {
+  %0 = "tf.Cast"(%arg0) : (tensor<f32>) -> tensor<i32>
+  %1 = "SomeOp" (%arg1) : (tensor<i32>) -> tensor<i32>
+  %2 = "tf.Add"(%0, %1) : (tensor<i32>, tensor<i32>) -> tensor<i32>
+  return %2 : tensor<i32>
+}
+```
+
+will produce tf_device::opCluster enclosing tf.Add and tf.Neg:
+
+```mlir
+func @cluster_oplist(%arg0: tensor<f32>, %arg1: tensor<i32>) -> tensor<i32> {
+  %0 = "SomeOp"(%arg1) : (tensor<i32>) -> tensor<i32>
+  %1 = "tf_device.cluster"() ( {
+    %2 = "tf.Cast"(%arg0) : (tensor<f32>) -> tensor<i32>
+    %3 = "tf.Add"(%2, %0) : (tensor<i32>, tensor<i32>) -> tensor<i32>
+    tf_device.return %3 : tensor<i32>
+  }) : () -> tensor<i32>
+  return %1 : tensor<i32>
+}
+```
+
+#### Options
+```
+-oplist : Cluster listed ops when they form a single use def-use chain, such that each op's single user is the next op in the list.
+```
 ### `-tf-device-cluster-outlining`: Outlines regions of tf_device.cluster operations
 This pass outlines the body of a `tf_device.cluster` into a function and
 replaces the `tf_device.cluster` op with an equivalent `tf_device.cluster_func`