1 files changed, 67 insertions, 0 deletions
diff --git a/tensorflow/compiler/xla/legacy_flags/llvm_backend_flags.cc b/tensorflow/compiler/xla/legacy_flags/llvm_backend_flags.cc
new file mode 100644
index 0000000000..c8a71b284f
--- /dev/null
+++ b/tensorflow/compiler/xla/legacy_flags/llvm_backend_flags.cc
@@ -0,0 +1,67 @@
+/* Copyright 2017 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.
+==============================================================================*/
+
+// Legacy flags associated with XLA's use of LLVM for code generation.
+
+#include <mutex>  // NOLINT(build/c++11): only using std::call_once, not mutex.
+#include <vector>
+
+#include "tensorflow/compiler/xla/legacy_flags/llvm_backend_flags.h"
+#include "tensorflow/compiler/xla/legacy_flags/parse_flags_from_env.h"
+#include "tensorflow/core/platform/types.h"
+#include "tensorflow/core/util/command_line_flags.h"
+
+namespace xla {
+namespace legacy_flags {
+
+// Pointers to the parsed value of the flags and flag descriptors, initialized
+// via flags_init.
+static LlvmBackendFlags* flags;
+static std::vector<tensorflow::Flag>* flag_list;
+static std::once_flag flags_init;
+
+// Allocate *flags.  Called via call_once(&flags_init,...).
+static void AllocateFlags() {
+  flags = new LlvmBackendFlags;
+  flags->xla_fast_math = true;
+  flags->xla_precision_losing_optimizations = true;
+  flag_list = new std::vector<tensorflow::Flag>({
+      tensorflow::Flag(
+          "xla_precision_losing_optimizations",
+          &flags->xla_precision_losing_optimizations,
+          "Allows llvm to make transformations that reduce the precision of "
+          "floating-point computations. This is equivalent to clang's "
+          "-funsafe-math-optimizations flag."),
+      tensorflow::Flag(
+          "xla_fast_math", &flags->xla_fast_math,
+          "Allows llvm to make all manner of unsafe floating-point "
+          "optimizations, including assuming that NaN and Inf don't appear.  "
+          "This is equivalent to clang's -ffast-math flag."),
+  });
+  ParseFlagsFromEnv(*flag_list);
+}
+
+void AppendLlvmBackendFlags(std::vector<tensorflow::Flag>* append_to) {
+  std::call_once(flags_init, &AllocateFlags);
+  append_to->insert(append_to->end(), flag_list->begin(), flag_list->end());
+}
+
+LlvmBackendFlags* GetLlvmBackendFlags() {
+  std::call_once(flags_init, &AllocateFlags);
+  return flags;
+}
+
+}  // namespace legacy_flags
+}  // namespace xla