Locate libdevice files for OSS build.

1. Created open-source target libdevice_root that wraps all libdevice files.

2. platform/posix/cuda_libdevice_path depends on the libdevice_root target.

3. Added cuda_libdevice_path_test that verifies libdevice files exist in the
computed libdevice directory.
Change: 141237087

tensorflow/core/BUILD

@@ -1802,6 +1802,20 @@ tf_cc_tests_gpu(
     ],
 )
 
+tf_cc_test_gpu(
+    name = "cuda_libdevice_path_test",
+    size = "small",
+    srcs = ["platform/cuda_libdevice_path_test.cc"],
+    linkstatic = tf_kernel_tests_linkstatic(),
+    tags = tf_cuda_tests_tags(),
+    deps = [
+        ":cuda_libdevice_path",
+        ":lib",
+        ":test",
+        ":test_main",
+    ],
+)
+
 tf_cc_test_gpu(
     name = "memory_types_test",
     size = "small",

tensorflow/core/platform/cuda_libdevice_path_test.cc

@@ -0,0 +1,36 @@
+/* Copyright 2016 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/core/platform/cuda_libdevice_path.h"
+
+#include "tensorflow/core/lib/core/status_test_util.h"
+#include "tensorflow/core/lib/io/path.h"
+#include "tensorflow/core/platform/env.h"
+#include "tensorflow/core/platform/test.h"
+
+namespace tensorflow {
+
+#if GOOGLE_CUDA
+TEST(CudaLibdevicePathTest, LibdevicePath) {
+  VLOG(2) << "Libdevice root = " << LibdeviceRoot();
+  std::vector<string> libdevice_files;
+  TF_EXPECT_OK(Env::Default()->GetMatchingPaths(
+      io::JoinPath(LibdeviceRoot(), "libdevice.compute_*.bc"),
+      &libdevice_files));
+  EXPECT_LT(0, libdevice_files.size());
+}
+#endif
+
+}  // namespace tensorflow

tensorflow/core/platform/default/build_config.bzl

@@ -143,7 +143,7 @@ def tf_additional_cupti_wrapper_deps():
   return ["//tensorflow/core/platform/default/gpu:cupti_wrapper"]
 
 def tf_additional_libdevice_data():
-  return []
+  return ["@local_config_cuda//cuda:libdevice_root"]
 
 def tf_additional_libdevice_deps():
   return []

tensorflow/core/platform/default/cuda_libdevice_path.cc

@@ -15,11 +15,24 @@ limitations under the License.
 
 #include "tensorflow/core/platform/cuda_libdevice_path.h"
 
+#include <stdlib.h>
+
+#include "tensorflow/core/lib/strings/strcat.h"
+#include "tensorflow/core/platform/default/logging.h"
+
 namespace tensorflow {
 
 string CudaRoot() {
-  // TODO(b/33147798): Compute the CUDA root for open-source build.
+  // 'bazel test' sets TEST_SRCDIR.
-  return ".";
+  const string kRelativeCudaRoot = "local_config_cuda/cuda";
+  const char* env = getenv("TEST_SRCDIR");
+  if (env && env[0] != '\0') {
+    return strings::StrCat(env, "/", kRelativeCudaRoot);
+  } else {
+    LOG(WARNING) << "TEST_SRCDIR environment variable not set: "
+                 << "using $PWD/" << kRelativeCudaRoot << "as the CUDA root.";
+    return kRelativeCudaRoot;
+  }
 }
 
 }  // namespace tensorflow

third_party/gpus/cuda/BUILD.tpl

@@ -160,3 +160,9 @@ cc_library(
     ],
     visibility = ["//visibility:public"],
 )
+
+cc_library(
+    name = "libdevice_root",
+    data = glob(["nvvm/libdevice/*.bc"]),
+    visibility = ["//visibility:public"],
+)