[wasm] Add expm1

tfjs-backend-wasm/src/cc/BUILD.bazel

@@ -851,6 +851,16 @@ tfjs_cc_library(
     ],
 )
 
+tfjs_cc_library(
+    name = "Expm1",
+    srcs = ["kernels/Expm1.cc"],
+    deps = [
+        ":backend",
+        ":unary",
+        ":util",
+    ],
+)
+
 tfjs_cc_library(
     name = "FlipLeftRight",
     srcs = ["kernels/FlipLeftRight.cc"],

tfjs-backend-wasm/src/cc/kernels/Expm1.cc

@@ -0,0 +1,57 @@
+/* Copyright 2023 Google LLC.
+ * 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 "tfjs-backend-wasm/src/cc/backend.h"
+#include "tfjs-backend-wasm/src/cc/unary.h"
+#include "tfjs-backend-wasm/src/cc/util.h"
+
+namespace {
+
+template <typename T>
+inline float expm1_impl(T n) {
+  return std::expm1f(static_cast<float>(n));
+}
+
+}  // namespace
+
+namespace tfjs {
+namespace wasm {
+// We use C-style API to interface with Javascript.
+extern "C" {
+
+#ifdef __EMSCRIPTEN__
+EMSCRIPTEN_KEEPALIVE
+#endif
+void Expm1(const int x_id, const DType dtype, const int out_id) {
+  switch (dtype) {
+    case DType::float32:
+      unary_f32(x_id, out_id, expm1_impl<float>);
+      break;
+    case DType::int32:
+      unary_i32_with_f32_out(x_id, out_id, expm1_impl<int>);
+      break;
+    default:
+      util::warn("Expm1 for tensor id %d failed. Unsupported dtype %d", x_id,
+                 dtype);
+  }
+}
+
+}  // extern "C"
+}  // namespace wasm
+}  // namespace tfjs

tfjs-backend-wasm/src/kernels/Expm1.ts

@@ -0,0 +1,22 @@
+/**
+ * @license
+ * Copyright 2023 Google LLC.
+ * 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 {Expm1, KernelConfig} from '@tensorflow/tfjs-core';
+
+import {createUnaryKernelConfig} from './unary_kernel';
+
+export const expm1Config: KernelConfig =
+    createUnaryKernelConfig(Expm1, 'float32');

tfjs-backend-wasm/src/register_all_kernels.ts

@@ -63,6 +63,7 @@ import {eluGradConfig} from './kernels/EluGrad';
 import {equalConfig} from './kernels/Equal';
 import {expConfig} from './kernels/Exp';
 import {expandDimsConfig} from './kernels/ExpandDims';
+import {expm1Config} from './kernels/Expm1';
 import {fillConfig} from './kernels/Fill';
 import {flipLeftRightConfig} from './kernels/FlipLeftRight';
 import {floorConfig} from './kernels/Floor';
@@ -209,6 +210,7 @@ const kernelConfigs: KernelConfig[] = [
   equalConfig,
   expConfig,
   expandDimsConfig,
+  expm1Config,
   fillConfig,
   flipLeftRightConfig,
   floorConfig,

tfjs-backend-wasm/src/setup_test.ts

@@ -407,6 +407,7 @@ const TEST_FILTERS: TestFilter[] = [
   {include: 'softplus '},
   {include: 'linspace'},
   {include: 'bincount'},
+  {include: 'expm1 '},
 ];
 
 const customInclude = (testName: string) => {