Provides an environment variable via TF_XLA_FLAGS to turn on the MLIR bridge.

PiperOrigin-RevId: 316116765
Change-Id: I005c5b6712a4e7cdd72f4302caae93f58c5f840e

tensorflow/compiler/jit/flags.cc

@@ -33,6 +33,7 @@ MarkForCompilationPassFlags* mark_for_compilation_flags;
 XlaDeviceFlags* device_flags;
 XlaOpsCommonFlags* ops_flags;
 IntroduceFloatingPointJitterPassFlags* jitter_flags;
+MlirCommonFlags* mlir_flags;
 
 std::vector<Flag>* flag_list;
 absl::once_flag flags_init;
@@ -166,6 +167,9 @@ void AllocateAndParseFlags() {
   jitter_flags = new IntroduceFloatingPointJitterPassFlags;
   jitter_flags->jitter_amount = 1e-5;
 
+  mlir_flags = new MlirCommonFlags;
+  mlir_flags->tf_mlir_enable_mlir_bridge = false;
+
   auto setter_for_jitter_tensor_names = [](string sequence) {
     jitter_flags->tensor_names = absl::StrSplit(sequence, ',');
     return true;
@@ -211,7 +215,11 @@ void AllocateAndParseFlags() {
        Flag("tf_introduce_floating_point_jitter_amount",
             &jitter_flags->jitter_amount,
             "The amount of jitter to introduce.  This amount is added to each "
-            "element in the tensors named in `tensor_names.")});
+            "element in the tensors named in `tensor_names."),
+
+       Flag("tf_mlir_enable_mlir_bridge",
+            &mlir_flags->tf_mlir_enable_mlir_bridge,
+            "Enables experimental MLIR-Based TensorFlow Compiler Bridge.")});
 
   AppendMarkForCompilationPassFlagsInternal(flag_list);
   xla::ParseFlagsFromEnvAndDieIfUnknown("TF_XLA_FLAGS", *flag_list);
@@ -250,6 +258,11 @@ GetIntroduceFloatingPointJitterPassFlags() {
   return *jitter_flags;
 }
 
+MlirCommonFlags* GetMlirCommonFlags() {
+  absl::call_once(flags_init, &AllocateAndParseFlags);
+  return mlir_flags;
+}
+
 void AppendMarkForCompilationPassFlags(std::vector<Flag>* flag_list) {
   absl::call_once(flags_init, &AllocateAndParseFlags);
   AppendMarkForCompilationPassFlagsInternal(flag_list);

tensorflow/compiler/jit/flags.h

@@ -133,6 +133,11 @@ struct IntroduceFloatingPointJitterPassFlags {
   std::vector<string> tensor_names;
 };
 
+// Flags for common MLIR configurations.
+struct MlirCommonFlags {
+  bool tf_mlir_enable_mlir_bridge;
+};
+
 // Return a pointer to the DumpGraphFlags struct;
 // repeated calls return the same pointer.
 // This should be called only after Flags::Parse() has returned.
@@ -148,6 +153,8 @@ const XlaOpsCommonFlags& GetXlaOpsCommonFlags();
 const IntroduceFloatingPointJitterPassFlags&
 GetIntroduceFloatingPointJitterPassFlags();
 
+MlirCommonFlags* GetMlirCommonFlags();
+
 // Appends the flag definitions associated with
 // MarkForCompilationPassFlags/DumpGraphFlags to `flag_list`.
 //

tensorflow/python/eager/context.py

@@ -451,7 +451,6 @@ class Context(object):
     self._inter_op_parallelism_threads = None
     self._soft_device_placement = None
     self._log_device_placement = None
-    self._enable_mlir_bridge = None
     self._enable_mlir_graph_optimization = None
     self._optimizer_experimental_options = {}
 
@@ -927,8 +926,7 @@ class Context(object):
     if self._log_device_placement is not None:
       config.log_device_placement = self._log_device_placement
 
-    if self._enable_mlir_bridge is not None:
-      config.experimental.enable_mlir_bridge = self._enable_mlir_bridge
+    config.experimental.enable_mlir_bridge = pywrap_tfe.TF_IsMlirBridgeEnabled()
     if self._enable_mlir_graph_optimization is not None:
       config.experimental.enable_mlir_graph_optimization = (
           self._enable_mlir_graph_optimization)
@@ -1466,7 +1464,7 @@ class Context(object):
 
   @property
   def enable_mlir_bridge(self):
-    return self._enable_mlir_bridge
+    return pywrap_tfe.TF_IsMlirBridgeEnabled()
 
   @property
   def enable_mlir_graph_optimization(self):
@@ -1474,7 +1472,7 @@ class Context(object):
 
   @enable_mlir_bridge.setter
   def enable_mlir_bridge(self, enabled):
-    self._enable_mlir_bridge = enabled
+    pywrap_tfe.TF_EnableMlirBridge(enabled)
     self._thread_local_data.function_call_options = None
 
   @enable_mlir_graph_optimization.setter

tensorflow/python/tfe_wrapper.cc

@@ -364,6 +364,14 @@ PYBIND11_MODULE(_pywrap_tfe, m) {
   m.def("TF_SetXlaMinClusterSize", &TF_SetXlaMinClusterSize);
   m.def("TF_IsXlaEnabled", [] { return tensorflow::IsXlaEnabled(); });
 
+  // MLIR Logic
+  m.def("TF_IsMlirBridgeEnabled", [] {
+    return tensorflow::GetMlirCommonFlags()->tf_mlir_enable_mlir_bridge;
+  });
+  m.def("TF_EnableMlirBridge", [](bool enabled) {
+    tensorflow::GetMlirCommonFlags()->tf_mlir_enable_mlir_bridge = enabled;
+  });
+
   // // TFE_Context Logic
   m.def(
       "TFE_NewContext",