[WASM] Add exp (#2517)

FEATURE

Author: lonelyclick

tfjs-backend-wasm/src/cc/BUILD

@@ -415,6 +415,15 @@ tfjs_cc_library(
   ],
 )
 
+tfjs_cc_library(
+  name = "Exp",
+  srcs = ["kernels/Exp.cc"],
+  deps = [
+    ":backend",
+    ":unary",
+  ],
+)
+
 tfjs_cc_library(
   name = "util",
   hdrs = ["util.h"],

tfjs-backend-wasm/src/cc/kernels/Exp.cc

@@ -0,0 +1,36 @@
+/* Copyright 2019 Google Inc. 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.
+ * ===========================================================================*/
+
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+#endif
+
+#include <cmath>
+
+#include "src/cc/backend.h"
+#include "src/cc/unary.h"
+
+namespace tfjs {
+namespace wasm {
+// We use C-style API to interface with Javascript.
+extern "C" {
+
+#ifdef __EMSCRIPTEN__
+EMSCRIPTEN_KEEPALIVE
+#endif
+void Exp(const int x_id, const int out_id) { unary(x_id, out_id, std::exp); }
+
+}  // extern "C"
+}  // namespace wasm
+}  // namespace tfjs

tfjs-backend-wasm/src/kernels/Exp.ts

@@ -0,0 +1,19 @@
+/**
+ * @license
+ * Copyright 2019 Google Inc. 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.
+ * =============================================================================
+ */
+
+import { registerUnaryKernel } from './unary_kernel';
+registerUnaryKernel('Exp');

tfjs-backend-wasm/src/kernels/all_kernels.ts

@@ -51,3 +51,4 @@ import './Slice';
 import './Square';
 import './Sub';
 import './Transpose';
+import './Exp';