From f5ed694a5d7a001b8a68e654947e8a70b09bd90f Mon Sep 17 00:00:00 2001
From: Ann Yuan <annyuan@gmail.com>
Date: Fri, 26 Jun 2020 14:21:40 -0400
Subject: [PATCH 01/13] init

---
 tfjs-backend-wasm/src/kernels/Reverse.ts | 49 ++++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 tfjs-backend-wasm/src/kernels/Reverse.ts

diff --git a/tfjs-backend-wasm/src/kernels/Reverse.ts b/tfjs-backend-wasm/src/kernels/Reverse.ts
new file mode 100644
index 00000000000..94677c41f70
--- /dev/null
+++ b/tfjs-backend-wasm/src/kernels/Reverse.ts
@@ -0,0 +1,49 @@
+/**
+ * @license
+ * Copyright 2020 Google LLC. 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 {backend_util, buffer, NamedAttrMap, NamedTensorInfoMap, registerKernel, Reverse, ReverseAttrs, ReverseInputs, slice_util, TensorInfo, util} from '@tensorflow/tfjs-core';
+
+import {BackendWasm} from '../backend_wasm';
+
+export function reverse(args: {
+  inputs: NamedTensorInfoMap,
+  backend: BackendWasm,
+  attrs: NamedAttrMap
+}): TensorInfo {
+  const {inputs, backend, attrs} = args;
+  const {x} = inputs as {} as ReverseInputs;
+  const {dims} = attrs as {} as ReverseAttrs;
+
+  const axes = util.parseAxisParam(dims, x.shape);
+
+  const out = backend.makeOutput(x.shape, x.dtype);
+  const xVals = backend.typedArrayFromHeap(x);
+  const outVals = backend.typedArrayFromHeap(out);
+  const outBuf = buffer(x.shape, x.dtype, outVals);
+
+  for (let i = 0; i < outVals.length; i++) {
+    const outLoc = outBuf.indexToLoc(i);
+    const inLoc = outLoc.slice();
+    axes.forEach(ax => inLoc[ax] = x.shape[ax] - 1 - inLoc[ax]);
+    // let inPos = 0;
+    outBuf.set(xVals[0], ...outLoc);
+  }
+
+  return out;
+}
+
+registerKernel({kernelName: Reverse, backendName: 'wasm', kernelFunc: reverse});

From 73f6d28431d0e73663c00fcce6ccadc0b01699eb Mon Sep 17 00:00:00 2001
From: Ann Yuan <annyuan@gmail.com>
Date: Sun, 28 Jun 2020 13:31:59 -0400
Subject: [PATCH 02/13] clean

---
 tfjs-backend-wasm/src/kernels/Reverse.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tfjs-backend-wasm/src/kernels/Reverse.ts b/tfjs-backend-wasm/src/kernels/Reverse.ts
index 94677c41f70..fcb57b29510 100644
--- a/tfjs-backend-wasm/src/kernels/Reverse.ts
+++ b/tfjs-backend-wasm/src/kernels/Reverse.ts
@@ -15,7 +15,7 @@
  * =============================================================================
  */
 
-import {backend_util, buffer, NamedAttrMap, NamedTensorInfoMap, registerKernel, Reverse, ReverseAttrs, ReverseInputs, slice_util, TensorInfo, util} from '@tensorflow/tfjs-core';
+import {buffer, NamedAttrMap, NamedTensorInfoMap, registerKernel, Reverse, ReverseAttrs, ReverseInputs, TensorInfo, util} from '@tensorflow/tfjs-core';
 
 import {BackendWasm} from '../backend_wasm';
 

From 30c292da09a676860bdd8f6d0c1ae5566e437277 Mon Sep 17 00:00:00 2001
From: Ann Yuan <annyuan@gmail.com>
Date: Mon, 29 Jun 2020 08:02:24 -0400
Subject: [PATCH 03/13] add reshape

---
 tfjs-backend-wasm/src/kernels/Reverse.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tfjs-backend-wasm/src/kernels/Reverse.ts b/tfjs-backend-wasm/src/kernels/Reverse.ts
index fcb57b29510..33f9b54c94a 100644
--- a/tfjs-backend-wasm/src/kernels/Reverse.ts
+++ b/tfjs-backend-wasm/src/kernels/Reverse.ts
@@ -18,6 +18,7 @@
 import {buffer, NamedAttrMap, NamedTensorInfoMap, registerKernel, Reverse, ReverseAttrs, ReverseInputs, TensorInfo, util} from '@tensorflow/tfjs-core';
 
 import {BackendWasm} from '../backend_wasm';
+import {reshape} from './Reshape';
 
 export function reverse(args: {
   inputs: NamedTensorInfoMap,
@@ -30,6 +31,8 @@ export function reverse(args: {
 
   const axes = util.parseAxisParam(dims, x.shape);
 
+  // TODO: ADD CLONE
+
   const out = backend.makeOutput(x.shape, x.dtype);
   const xVals = backend.typedArrayFromHeap(x);
   const outVals = backend.typedArrayFromHeap(out);
@@ -43,7 +46,7 @@ export function reverse(args: {
     outBuf.set(xVals[0], ...outLoc);
   }
 
-  return out;
+  return reshape({inputs: {x: out}, attrs: {shape: x.shape}, backend});
 }
 
 registerKernel({kernelName: Reverse, backendName: 'wasm', kernelFunc: reverse});

From e8fff8f85c47df86f1354f13a6ebfa0c426ee58e Mon Sep 17 00:00:00 2001
From: Ann Yuan <annyuan@gmail.com>
Date: Mon, 29 Jun 2020 08:42:21 -0400
Subject: [PATCH 04/13] reverse

---
 tfjs-backend-wasm/src/cc/BUILD               | 10 +++
 tfjs-backend-wasm/src/cc/kernels/Reverse.cc  | 69 ++++++++++++++++++++
 tfjs-backend-wasm/src/kernels/Reverse.ts     | 44 +++++++++----
 tfjs-backend-wasm/src/kernels/all_kernels.ts |  1 +
 4 files changed, 111 insertions(+), 13 deletions(-)
 create mode 100644 tfjs-backend-wasm/src/cc/kernels/Reverse.cc

diff --git a/tfjs-backend-wasm/src/cc/BUILD b/tfjs-backend-wasm/src/cc/BUILD
index 0ef8f64fc2c..a22d9204bd8 100644
--- a/tfjs-backend-wasm/src/cc/BUILD
+++ b/tfjs-backend-wasm/src/cc/BUILD
@@ -224,6 +224,7 @@ tfjs_cc_library(
         ":Relu",
         ":Relu6",
         ":ResizeBilinear",
+        ":Reverse",
         ":ScatterNd",
         ":SelectV2",
         ":Sigmoid",
@@ -746,6 +747,15 @@ tfjs_unit_test(
     ],
 )
 
+tfjs_cc_library(
+    name = "Reverse",
+    srcs = ["kernels/Reverse.cc"],
+    deps = [
+        ":backend",
+        ":util",
+    ],
+)
+
 tfjs_cc_library(
     name = "ScatterNd",
     srcs = ["kernels/ScatterNd.cc"],
diff --git a/tfjs-backend-wasm/src/cc/kernels/Reverse.cc b/tfjs-backend-wasm/src/cc/kernels/Reverse.cc
new file mode 100644
index 00000000000..d6ae4ab18f5
--- /dev/null
+++ b/tfjs-backend-wasm/src/cc/kernels/Reverse.cc
@@ -0,0 +1,69 @@
+/* Copyright 2019 Google LLC. 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 <cstddef>
+#include <vector>
+
+#include "src/cc/backend.h"
+#include "src/cc/util.h"
+
+namespace tfjs {
+namespace wasm {
+// We use C-style API to interface with Javascript.
+extern "C" {
+
+#ifdef __EMSCRIPTEN__
+EMSCRIPTEN_KEEPALIVE
+#endif
+void Reverse(const size_t x_id, const size_t* axes_ptr,
+             const size_t axes_length, const size_t* out_shape_ptr,
+             const size_t out_shape_length, const size_t out_id) {
+  auto out_shape =
+      std::vector<size_t>(out_shape_ptr, out_shape_ptr + out_shape_length);
+  auto axes = std::vector<size_t>(axes_ptr, axes_ptr + axes_length);
+
+  auto& x_info = backend::get_tensor_info(x_id);
+  const float* x_buf = x_info.f32();
+
+  size_t x_size = x_info.size;
+
+  const std::vector<size_t> out_strides =
+      tfjs::util::compute_strides(out_shape);
+
+  for (size_t i = 0; i < x_size; ++i) {
+    const std::vector<size_t> out_loc =
+        tfjs::util::offset_to_loc(i, out_strides);
+
+    for (size_t ax_i = 0; ax_i < axes_length; ++ax_i) {
+      size_t ax = axes[ax_i];
+    }
+
+    const std::vector<size_t> in_loc = out_loc;
+    for (size_t ax_i = 0; ax_i < axes_length; ++ax_i) {
+      size_t ax = axes[ax_i];
+      in_loc[ax] = out_shape[ax] - 1 - in_loc[ax];
+    }
+
+    const size_t x_position = tfjs::util::loc_to_offset(in_loc, out_strides);
+    out[i] = x_buf[x_position];
+  }
+}
+
+}  // extern "C"
+}  // namespace wasm
+}  // namespace tfjs
diff --git a/tfjs-backend-wasm/src/kernels/Reverse.ts b/tfjs-backend-wasm/src/kernels/Reverse.ts
index 33f9b54c94a..2dc0279917b 100644
--- a/tfjs-backend-wasm/src/kernels/Reverse.ts
+++ b/tfjs-backend-wasm/src/kernels/Reverse.ts
@@ -15,11 +15,26 @@
  * =============================================================================
  */
 
-import {buffer, NamedAttrMap, NamedTensorInfoMap, registerKernel, Reverse, ReverseAttrs, ReverseInputs, TensorInfo, util} from '@tensorflow/tfjs-core';
+import {NamedAttrMap, NamedTensorInfoMap, registerKernel, Reverse, ReverseAttrs, ReverseInputs, TensorInfo, util} from '@tensorflow/tfjs-core';
 
 import {BackendWasm} from '../backend_wasm';
 import {reshape} from './Reshape';
 
+let wasmReverse: (
+    xId: number, axes: Uint8Array, axesLength: number, outShape: Uint8Array,
+    outShapeLength: number, outId: number) => void;
+
+function setup(backend: BackendWasm) {
+  wasmReverse = backend.wasm.cwrap(Reverse, null, [
+    'number',  // x_id
+    'array',   // axes
+    'number',  // axes_length
+    'array',   // out_shape
+    'number',  // out_shape_length
+    'number'   // out_id
+  ]);
+}
+
 export function reverse(args: {
   inputs: NamedTensorInfoMap,
   backend: BackendWasm,
@@ -34,19 +49,22 @@ export function reverse(args: {
   // TODO: ADD CLONE
 
   const out = backend.makeOutput(x.shape, x.dtype);
-  const xVals = backend.typedArrayFromHeap(x);
-  const outVals = backend.typedArrayFromHeap(out);
-  const outBuf = buffer(x.shape, x.dtype, outVals);
-
-  for (let i = 0; i < outVals.length; i++) {
-    const outLoc = outBuf.indexToLoc(i);
-    const inLoc = outLoc.slice();
-    axes.forEach(ax => inLoc[ax] = x.shape[ax] - 1 - inLoc[ax]);
-    // let inPos = 0;
-    outBuf.set(xVals[0], ...outLoc);
-  }
+  const xId = backend.dataIdMap.get(x.dataId).id;
+  const outId = backend.dataIdMap.get(out.dataId).id;
+
+  const axesBytes = new Uint8Array(new Int32Array(axes).buffer);
+
+  const outShapeBytes = new Uint8Array(new Int32Array(x.shape));
+
+  wasmReverse(
+      xId, axesBytes, axes.length, outShapeBytes, x.shape.length, outId);
 
   return reshape({inputs: {x: out}, attrs: {shape: x.shape}, backend});
 }
 
-registerKernel({kernelName: Reverse, backendName: 'wasm', kernelFunc: reverse});
+registerKernel({
+  kernelName: Reverse,
+  backendName: 'wasm',
+  kernelFunc: reverse,
+  setupFunc: setup
+});
diff --git a/tfjs-backend-wasm/src/kernels/all_kernels.ts b/tfjs-backend-wasm/src/kernels/all_kernels.ts
index ee032cfc119..1f304465401 100644
--- a/tfjs-backend-wasm/src/kernels/all_kernels.ts
+++ b/tfjs-backend-wasm/src/kernels/all_kernels.ts
@@ -68,6 +68,7 @@ import './Relu';
 import './Relu6';
 import './Reshape';
 import './ResizeBilinear';
+import './Reverse';
 import './Rsqrt';
 import './SelectV2';
 import './ScatterNd';

From 870a946d99f7cb5ff7e82dd4a53abcf3e8c54294 Mon Sep 17 00:00:00 2001
From: Ann Yuan <annyuan@gmail.com>
Date: Mon, 29 Jun 2020 09:03:29 -0400
Subject: [PATCH 05/13] setup

---
 tfjs-backend-wasm/src/cc/kernels/Reverse.cc | 11 +++----
 tfjs-backend-wasm/src/index_test.ts         | 34 +++++++++++++++++++--
 tfjs-backend-wasm/src/kernels/Reverse.ts    |  3 +-
 tfjs-backend-wasm/src/setup_test.ts         |  1 +
 4 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/tfjs-backend-wasm/src/cc/kernels/Reverse.cc b/tfjs-backend-wasm/src/cc/kernels/Reverse.cc
index d6ae4ab18f5..7f1459decc2 100644
--- a/tfjs-backend-wasm/src/cc/kernels/Reverse.cc
+++ b/tfjs-backend-wasm/src/cc/kernels/Reverse.cc
@@ -40,6 +40,9 @@ void Reverse(const size_t x_id, const size_t* axes_ptr,
   auto& x_info = backend::get_tensor_info(x_id);
   const float* x_buf = x_info.f32();
 
+  auto& out_info = backend::get_tensor_info_out(out_id);
+  float* out_buf = out_info.f32_write();
+
   size_t x_size = x_info.size;
 
   const std::vector<size_t> out_strides =
@@ -49,18 +52,14 @@ void Reverse(const size_t x_id, const size_t* axes_ptr,
     const std::vector<size_t> out_loc =
         tfjs::util::offset_to_loc(i, out_strides);
 
-    for (size_t ax_i = 0; ax_i < axes_length; ++ax_i) {
-      size_t ax = axes[ax_i];
-    }
-
-    const std::vector<size_t> in_loc = out_loc;
+    std::vector<size_t> in_loc = out_loc;
     for (size_t ax_i = 0; ax_i < axes_length; ++ax_i) {
       size_t ax = axes[ax_i];
       in_loc[ax] = out_shape[ax] - 1 - in_loc[ax];
     }
 
     const size_t x_position = tfjs::util::loc_to_offset(in_loc, out_strides);
-    out[i] = x_buf[x_position];
+    out_buf[i] = x_buf[x_position];
   }
 }
 
diff --git a/tfjs-backend-wasm/src/index_test.ts b/tfjs-backend-wasm/src/index_test.ts
index d7f2bd6e914..27f68c9a6d3 100644
--- a/tfjs-backend-wasm/src/index_test.ts
+++ b/tfjs-backend-wasm/src/index_test.ts
@@ -73,8 +73,8 @@ describeWithFlags('wasm init', BROWSER_ENVS, () => {
     }, 100);
 
     // Silences backend registration warnings.
-    spyOn(console, 'warn');
-    spyOn(console, 'log');
+    // spyOn(console, 'warn');
+    // spyOn(console, 'log');
   });
 
   afterEach(() => {
@@ -138,4 +138,34 @@ describeWithFlags('wasm init', BROWSER_ENVS, () => {
     expect(() => setWasmPath('too/late'))
         .toThrowError(/The WASM backend was already initialized. Make sure/);
   });
+
+  it('accepts a tensor-like object', async () => {
+    const input = [1, 2, 3];
+    const result = tf.reverse(input);
+    expect(result.shape).toEqual([3]);
+    const data = await result.data();
+    console.log(data);
+    // expectArraysClose(await result.data(), [3, 2, 1]);
+  });
+
+  fit('reverse a 4D array at axis [0]', async () => {
+    const shape: [number, number, number, number] = [3, 2, 3, 4];
+    const data = [
+      0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  10, 11, 12, 13, 14, 15, 16, 17,
+      18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
+      36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53,
+      54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71
+    ];
+    const input = tf.tensor4d(data, shape);
+    const result = tf.reverse4d(input, [0]);
+    expect(result.shape).toEqual(input.shape);
+    const out = await result.data();
+    console.log(Array.from(out));
+    // expectArraysClose(await result.data(), [
+    //   48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65,
+    //   66, 67, 68, 69, 70, 71, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
+    //   36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 0,  1,  2,  3,  4,  5,
+    //   6,  7,  8,  9,  10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23
+    // ]);
+  });
 });
diff --git a/tfjs-backend-wasm/src/kernels/Reverse.ts b/tfjs-backend-wasm/src/kernels/Reverse.ts
index 2dc0279917b..fe700fd08c9 100644
--- a/tfjs-backend-wasm/src/kernels/Reverse.ts
+++ b/tfjs-backend-wasm/src/kernels/Reverse.ts
@@ -53,9 +53,10 @@ export function reverse(args: {
   const outId = backend.dataIdMap.get(out.dataId).id;
 
   const axesBytes = new Uint8Array(new Int32Array(axes).buffer);
-
   const outShapeBytes = new Uint8Array(new Int32Array(x.shape));
 
+  console.log(axes, x.shape);
+
   wasmReverse(
       xId, axesBytes, axes.length, outShapeBytes, x.shape.length, outId);
 
diff --git a/tfjs-backend-wasm/src/setup_test.ts b/tfjs-backend-wasm/src/setup_test.ts
index 0c14b49c728..8483f83f2d6 100644
--- a/tfjs-backend-wasm/src/setup_test.ts
+++ b/tfjs-backend-wasm/src/setup_test.ts
@@ -308,6 +308,7 @@ const TEST_FILTERS: TestFilter[] = [
       'axis=0',  // Reduction not supported along inner dimensions.
     ]
   },
+  {startsWith: 'reverse'},
   {startsWith: 'sum '},
   {
     startsWith: 'logicalAnd ',

From efee4bcadc31746c43189f3fd43c59b49c7b6578 Mon Sep 17 00:00:00 2001
From: Ann Yuan <annyuan@gmail.com>
Date: Mon, 29 Jun 2020 09:46:53 -0400
Subject: [PATCH 06/13] fix

---
 tfjs-backend-wasm/src/index_test.ts      | 30 ------------------------
 tfjs-backend-wasm/src/kernels/Reverse.ts |  4 +---
 2 files changed, 1 insertion(+), 33 deletions(-)

diff --git a/tfjs-backend-wasm/src/index_test.ts b/tfjs-backend-wasm/src/index_test.ts
index 27f68c9a6d3..67be9de62af 100644
--- a/tfjs-backend-wasm/src/index_test.ts
+++ b/tfjs-backend-wasm/src/index_test.ts
@@ -138,34 +138,4 @@ describeWithFlags('wasm init', BROWSER_ENVS, () => {
     expect(() => setWasmPath('too/late'))
         .toThrowError(/The WASM backend was already initialized. Make sure/);
   });
-
-  it('accepts a tensor-like object', async () => {
-    const input = [1, 2, 3];
-    const result = tf.reverse(input);
-    expect(result.shape).toEqual([3]);
-    const data = await result.data();
-    console.log(data);
-    // expectArraysClose(await result.data(), [3, 2, 1]);
-  });
-
-  fit('reverse a 4D array at axis [0]', async () => {
-    const shape: [number, number, number, number] = [3, 2, 3, 4];
-    const data = [
-      0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  10, 11, 12, 13, 14, 15, 16, 17,
-      18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
-      36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53,
-      54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71
-    ];
-    const input = tf.tensor4d(data, shape);
-    const result = tf.reverse4d(input, [0]);
-    expect(result.shape).toEqual(input.shape);
-    const out = await result.data();
-    console.log(Array.from(out));
-    // expectArraysClose(await result.data(), [
-    //   48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65,
-    //   66, 67, 68, 69, 70, 71, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
-    //   36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 0,  1,  2,  3,  4,  5,
-    //   6,  7,  8,  9,  10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23
-    // ]);
-  });
 });
diff --git a/tfjs-backend-wasm/src/kernels/Reverse.ts b/tfjs-backend-wasm/src/kernels/Reverse.ts
index fe700fd08c9..77abb014543 100644
--- a/tfjs-backend-wasm/src/kernels/Reverse.ts
+++ b/tfjs-backend-wasm/src/kernels/Reverse.ts
@@ -53,9 +53,7 @@ export function reverse(args: {
   const outId = backend.dataIdMap.get(out.dataId).id;
 
   const axesBytes = new Uint8Array(new Int32Array(axes).buffer);
-  const outShapeBytes = new Uint8Array(new Int32Array(x.shape));
-
-  console.log(axes, x.shape);
+  const outShapeBytes = new Uint8Array(new Int32Array(x.shape).buffer);
 
   wasmReverse(
       xId, axesBytes, axes.length, outShapeBytes, x.shape.length, outId);

From 20ca72b736f9dff82678982a47a91a612b5f58a9 Mon Sep 17 00:00:00 2001
From: Ann Yuan <annyuan@gmail.com>
Date: Mon, 29 Jun 2020 09:48:25 -0400
Subject: [PATCH 07/13] clean

---
 tfjs-backend-wasm/src/index_test.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tfjs-backend-wasm/src/index_test.ts b/tfjs-backend-wasm/src/index_test.ts
index 67be9de62af..d7f2bd6e914 100644
--- a/tfjs-backend-wasm/src/index_test.ts
+++ b/tfjs-backend-wasm/src/index_test.ts
@@ -73,8 +73,8 @@ describeWithFlags('wasm init', BROWSER_ENVS, () => {
     }, 100);
 
     // Silences backend registration warnings.
-    // spyOn(console, 'warn');
-    // spyOn(console, 'log');
+    spyOn(console, 'warn');
+    spyOn(console, 'log');
   });
 
   afterEach(() => {

From 679c90e55eccf03dacc69cd5ac9e8f68385de006 Mon Sep 17 00:00:00 2001
From: Ann Yuan <annyuan@gmail.com>
Date: Mon, 29 Jun 2020 10:09:04 -0400
Subject: [PATCH 08/13] add clone

---
 tfjs-backend-wasm/src/backend_wasm.ts    | 6 +++++-
 tfjs-backend-wasm/src/kernels/Reverse.ts | 4 +++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/tfjs-backend-wasm/src/backend_wasm.ts b/tfjs-backend-wasm/src/backend_wasm.ts
index 0299073da66..3ecdd8c4fde 100644
--- a/tfjs-backend-wasm/src/backend_wasm.ts
+++ b/tfjs-backend-wasm/src/backend_wasm.ts
@@ -16,7 +16,7 @@
  */
 import './flags_wasm';
 
-import {backend_util, BackendTimingInfo, DataStorage, DataType, engine, env, KernelBackend, registerBackend, TensorInfo, util} from '@tensorflow/tfjs-core';
+import {backend_util, BackendTimingInfo, DataStorage, DataType, engine, env, KernelBackend, registerBackend, Tensor, TensorInfo, util} from '@tensorflow/tfjs-core';
 
 import {BackendWasmModule, WasmFactoryConfig} from '../wasm-out/tfjs-backend-wasm';
 import wasmFactorySimd from '../wasm-out/tfjs-backend-wasm-simd.js';
@@ -64,6 +64,10 @@ export class BackendWasm extends KernelBackend {
     return {kernelMs};
   }
 
+  clone(x: TensorInfo): Tensor {
+    return engine().makeTensorFromDataId(x.dataId, x.shape, x.dtype);
+  }
+
   move(
       dataId: DataId, values: backend_util.BackendValues, shape: number[],
       dtype: DataType): void {
diff --git a/tfjs-backend-wasm/src/kernels/Reverse.ts b/tfjs-backend-wasm/src/kernels/Reverse.ts
index 77abb014543..571f4a2bab7 100644
--- a/tfjs-backend-wasm/src/kernels/Reverse.ts
+++ b/tfjs-backend-wasm/src/kernels/Reverse.ts
@@ -46,7 +46,9 @@ export function reverse(args: {
 
   const axes = util.parseAxisParam(dims, x.shape);
 
-  // TODO: ADD CLONE
+  if (x.shape.length === 0) {
+    return backend.clone(x);
+  }
 
   const out = backend.makeOutput(x.shape, x.dtype);
   const xId = backend.dataIdMap.get(x.dataId).id;

From a8fd5392e5c7211d1c7c9f5325d1ef6db07a9288 Mon Sep 17 00:00:00 2001
From: Ann Yuan <annyuan@gmail.com>
Date: Mon, 29 Jun 2020 16:50:10 -0400
Subject: [PATCH 09/13] comments

---
 tfjs-backend-wasm/src/cc/kernels/Reverse.cc |  4 +---
 tfjs-backend-wasm/src/kernels/Reverse.ts    | 17 ++++++++---------
 tfjs-core/src/index.ts                      |  2 +-
 3 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/tfjs-backend-wasm/src/cc/kernels/Reverse.cc b/tfjs-backend-wasm/src/cc/kernels/Reverse.cc
index 7f1459decc2..7aa290639e8 100644
--- a/tfjs-backend-wasm/src/cc/kernels/Reverse.cc
+++ b/tfjs-backend-wasm/src/cc/kernels/Reverse.cc
@@ -49,10 +49,8 @@ void Reverse(const size_t x_id, const size_t* axes_ptr,
       tfjs::util::compute_strides(out_shape);
 
   for (size_t i = 0; i < x_size; ++i) {
-    const std::vector<size_t> out_loc =
-        tfjs::util::offset_to_loc(i, out_strides);
+    std::vector<size_t> in_loc = tfjs::util::offset_to_loc(i, out_strides);
 
-    std::vector<size_t> in_loc = out_loc;
     for (size_t ax_i = 0; ax_i < axes_length; ++ax_i) {
       size_t ax = axes[ax_i];
       in_loc[ax] = out_shape[ax] - 1 - in_loc[ax];
diff --git a/tfjs-backend-wasm/src/kernels/Reverse.ts b/tfjs-backend-wasm/src/kernels/Reverse.ts
index 571f4a2bab7..6d0aa6441cb 100644
--- a/tfjs-backend-wasm/src/kernels/Reverse.ts
+++ b/tfjs-backend-wasm/src/kernels/Reverse.ts
@@ -15,9 +15,10 @@
  * =============================================================================
  */
 
-import {NamedAttrMap, NamedTensorInfoMap, registerKernel, Reverse, ReverseAttrs, ReverseInputs, TensorInfo, util} from '@tensorflow/tfjs-core';
+import {ForwardFunc, registerKernel, Reverse, ReverseAttrs, ReverseInputs, TensorInfo, util} from '@tensorflow/tfjs-core';
 
 import {BackendWasm} from '../backend_wasm';
+
 import {reshape} from './Reshape';
 
 let wasmReverse: (
@@ -35,14 +36,12 @@ function setup(backend: BackendWasm) {
   ]);
 }
 
-export function reverse(args: {
-  inputs: NamedTensorInfoMap,
-  backend: BackendWasm,
-  attrs: NamedAttrMap
-}): TensorInfo {
+export function reverse(
+    args: {inputs: ReverseInputs, backend: BackendWasm, attrs: ReverseAttrs}):
+    TensorInfo {
   const {inputs, backend, attrs} = args;
-  const {x} = inputs as {} as ReverseInputs;
-  const {dims} = attrs as {} as ReverseAttrs;
+  const {x} = inputs;
+  const {dims} = attrs;
 
   const axes = util.parseAxisParam(dims, x.shape);
 
@@ -66,6 +65,6 @@ export function reverse(args: {
 registerKernel({
   kernelName: Reverse,
   backendName: 'wasm',
-  kernelFunc: reverse,
+  kernelFunc: reverse as ForwardFunc,
   setupFunc: setup
 });
diff --git a/tfjs-core/src/index.ts b/tfjs-core/src/index.ts
index 71756dda83b..2dd95b94200 100644
--- a/tfjs-core/src/index.ts
+++ b/tfjs-core/src/index.ts
@@ -71,7 +71,7 @@ export * from './globals';
 export * from './kernel_registry';
 export {customGrad, grad, grads, valueAndGrad, valueAndGrads, variableGrads} from './gradients';
 
-export {TimingInfo, MemoryInfo} from './engine';
+export {TimingInfo, MemoryInfo, ForwardFunc} from './engine';
 export {Environment, env, ENV} from './environment';
 export {Platform} from './platforms/platform';
 

From 36caabfb118ab24884371164916100853e22f120 Mon Sep 17 00:00:00 2001
From: Ann Yuan <annyuan@gmail.com>
Date: Mon, 29 Jun 2020 16:55:03 -0400
Subject: [PATCH 10/13] add register all

---
 tfjs-backend-wasm/src/index.ts                |  1 +
 tfjs-backend-wasm/src/kernels/Reverse.ts      |  6 ++--
 tfjs-backend-wasm/src/register_all_kernels.ts | 29 +++++++++++++++++++
 3 files changed, 33 insertions(+), 3 deletions(-)
 create mode 100644 tfjs-backend-wasm/src/register_all_kernels.ts

diff --git a/tfjs-backend-wasm/src/index.ts b/tfjs-backend-wasm/src/index.ts
index 5581dd7e02c..a2c1b2a4d48 100644
--- a/tfjs-backend-wasm/src/index.ts
+++ b/tfjs-backend-wasm/src/index.ts
@@ -16,6 +16,7 @@
  */
 
 import './kernels/all_kernels';
+import './register_all_kernels';
 
 export {BackendWasm, setWasmPath} from './backend_wasm';
 export {version as version_wasm} from './version';
diff --git a/tfjs-backend-wasm/src/kernels/Reverse.ts b/tfjs-backend-wasm/src/kernels/Reverse.ts
index 6d0aa6441cb..e9fc4ba9957 100644
--- a/tfjs-backend-wasm/src/kernels/Reverse.ts
+++ b/tfjs-backend-wasm/src/kernels/Reverse.ts
@@ -15,7 +15,7 @@
  * =============================================================================
  */
 
-import {ForwardFunc, registerKernel, Reverse, ReverseAttrs, ReverseInputs, TensorInfo, util} from '@tensorflow/tfjs-core';
+import {ForwardFunc, KernelConfig, Reverse, ReverseAttrs, ReverseInputs, TensorInfo, util} from '@tensorflow/tfjs-core';
 
 import {BackendWasm} from '../backend_wasm';
 
@@ -62,9 +62,9 @@ export function reverse(
   return reshape({inputs: {x: out}, attrs: {shape: x.shape}, backend});
 }
 
-registerKernel({
+export const reverseConfig: KernelConfig = {
   kernelName: Reverse,
   backendName: 'wasm',
   kernelFunc: reverse as ForwardFunc,
   setupFunc: setup
-});
+};
diff --git a/tfjs-backend-wasm/src/register_all_kernels.ts b/tfjs-backend-wasm/src/register_all_kernels.ts
new file mode 100644
index 00000000000..87c151df493
--- /dev/null
+++ b/tfjs-backend-wasm/src/register_all_kernels.ts
@@ -0,0 +1,29 @@
+/**
+ * @license
+ * Copyright 2020 Google LLC. 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.
+ * =============================================================================
+ */
+// We explicitly import the modular kernels so they get registered in the
+// global registry when we compile the library. A modular build would replace
+// the contents of this file and import only the kernels that are needed.
+import {KernelConfig, registerKernel} from '@tensorflow/tfjs-core';
+
+import {reverseConfig} from './kernels/Reverse';
+
+// List all kernel configs here
+const kernelConfigs: KernelConfig[] = [reverseConfig];
+
+for (const kernelConfig of kernelConfigs) {
+  registerKernel(kernelConfig);
+}

From b018b67dd1e4a023d0c82edb36e148bd78aa5ebc Mon Sep 17 00:00:00 2001
From: Ann Yuan <annyuan@gmail.com>
Date: Mon, 29 Jun 2020 17:03:36 -0400
Subject: [PATCH 11/13] fix

---
 tfjs-backend-wasm/src/kernels/Reverse.ts | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/tfjs-backend-wasm/src/kernels/Reverse.ts b/tfjs-backend-wasm/src/kernels/Reverse.ts
index e9fc4ba9957..94c836d770b 100644
--- a/tfjs-backend-wasm/src/kernels/Reverse.ts
+++ b/tfjs-backend-wasm/src/kernels/Reverse.ts
@@ -15,7 +15,7 @@
  * =============================================================================
  */
 
-import {ForwardFunc, KernelConfig, Reverse, ReverseAttrs, ReverseInputs, TensorInfo, util} from '@tensorflow/tfjs-core';
+import {KernelConfig, NamedAttrMap, NamedTensorInfoMap, Reverse, ReverseAttrs, ReverseInputs, TensorInfo, util} from '@tensorflow/tfjs-core';
 
 import {BackendWasm} from '../backend_wasm';
 
@@ -36,12 +36,14 @@ function setup(backend: BackendWasm) {
   ]);
 }
 
-export function reverse(
-    args: {inputs: ReverseInputs, backend: BackendWasm, attrs: ReverseAttrs}):
-    TensorInfo {
+export function reverse(args: {
+  inputs: NamedTensorInfoMap,
+  backend: BackendWasm,
+  attrs: NamedAttrMap
+}): TensorInfo {
   const {inputs, backend, attrs} = args;
-  const {x} = inputs;
-  const {dims} = attrs;
+  const {x} = inputs as {} as ReverseInputs;
+  const {dims} = attrs as {} as ReverseAttrs;
 
   const axes = util.parseAxisParam(dims, x.shape);
 
@@ -65,6 +67,6 @@ export function reverse(
 export const reverseConfig: KernelConfig = {
   kernelName: Reverse,
   backendName: 'wasm',
-  kernelFunc: reverse as ForwardFunc,
+  kernelFunc: reverse,
   setupFunc: setup
 };

From ab011c1e035b2ab13a9bb1747325eba622250226 Mon Sep 17 00:00:00 2001
From: Ann Yuan <annyuan@gmail.com>
Date: Tue, 30 Jun 2020 12:33:14 -0400
Subject: [PATCH 12/13] type

---
 tfjs-backend-wasm/src/kernels/Reverse.ts | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/tfjs-backend-wasm/src/kernels/Reverse.ts b/tfjs-backend-wasm/src/kernels/Reverse.ts
index 94c836d770b..6e2ed89c749 100644
--- a/tfjs-backend-wasm/src/kernels/Reverse.ts
+++ b/tfjs-backend-wasm/src/kernels/Reverse.ts
@@ -15,7 +15,7 @@
  * =============================================================================
  */
 
-import {KernelConfig, NamedAttrMap, NamedTensorInfoMap, Reverse, ReverseAttrs, ReverseInputs, TensorInfo, util} from '@tensorflow/tfjs-core';
+import {KernelConfig, KernelFunc, Reverse, ReverseAttrs, ReverseInputs, TensorInfo, util} from '@tensorflow/tfjs-core';
 
 import {BackendWasm} from '../backend_wasm';
 
@@ -36,14 +36,12 @@ function setup(backend: BackendWasm) {
   ]);
 }
 
-export function reverse(args: {
-  inputs: NamedTensorInfoMap,
-  backend: BackendWasm,
-  attrs: NamedAttrMap
-}): TensorInfo {
+export function reverse(
+    args: {inputs: ReverseInputs, backend: BackendWasm, attrs: ReverseAttrs}):
+    TensorInfo {
   const {inputs, backend, attrs} = args;
-  const {x} = inputs as {} as ReverseInputs;
-  const {dims} = attrs as {} as ReverseAttrs;
+  const {x} = inputs;
+  const {dims} = attrs;
 
   const axes = util.parseAxisParam(dims, x.shape);
 
@@ -67,6 +65,6 @@ export function reverse(args: {
 export const reverseConfig: KernelConfig = {
   kernelName: Reverse,
   backendName: 'wasm',
-  kernelFunc: reverse,
+  kernelFunc: reverse as {} as KernelFunc,
   setupFunc: setup
 };

From 607b5ef142ed7e292ae86508feec81ca51bf1252 Mon Sep 17 00:00:00 2001
From: Ann Yuan <annyuan@gmail.com>
Date: Mon, 6 Jul 2020 09:50:32 -0400
Subject: [PATCH 13/13] add clone

---
 tfjs-backend-wasm/src/backend_wasm.ts        |  6 +---
 tfjs-backend-wasm/src/kernels/Identity.ts    | 37 ++++++++++++++++++++
 tfjs-backend-wasm/src/kernels/Reverse.ts     |  3 +-
 tfjs-backend-wasm/src/kernels/all_kernels.ts |  1 +
 tfjs-core/src/ops/clone.ts                   |  9 +++--
 5 files changed, 47 insertions(+), 9 deletions(-)
 create mode 100644 tfjs-backend-wasm/src/kernels/Identity.ts

diff --git a/tfjs-backend-wasm/src/backend_wasm.ts b/tfjs-backend-wasm/src/backend_wasm.ts
index 3ecdd8c4fde..0299073da66 100644
--- a/tfjs-backend-wasm/src/backend_wasm.ts
+++ b/tfjs-backend-wasm/src/backend_wasm.ts
@@ -16,7 +16,7 @@
  */
 import './flags_wasm';
 
-import {backend_util, BackendTimingInfo, DataStorage, DataType, engine, env, KernelBackend, registerBackend, Tensor, TensorInfo, util} from '@tensorflow/tfjs-core';
+import {backend_util, BackendTimingInfo, DataStorage, DataType, engine, env, KernelBackend, registerBackend, TensorInfo, util} from '@tensorflow/tfjs-core';
 
 import {BackendWasmModule, WasmFactoryConfig} from '../wasm-out/tfjs-backend-wasm';
 import wasmFactorySimd from '../wasm-out/tfjs-backend-wasm-simd.js';
@@ -64,10 +64,6 @@ export class BackendWasm extends KernelBackend {
     return {kernelMs};
   }
 
-  clone(x: TensorInfo): Tensor {
-    return engine().makeTensorFromDataId(x.dataId, x.shape, x.dtype);
-  }
-
   move(
       dataId: DataId, values: backend_util.BackendValues, shape: number[],
       dtype: DataType): void {
diff --git a/tfjs-backend-wasm/src/kernels/Identity.ts b/tfjs-backend-wasm/src/kernels/Identity.ts
new file mode 100644
index 00000000000..edfdb824914
--- /dev/null
+++ b/tfjs-backend-wasm/src/kernels/Identity.ts
@@ -0,0 +1,37 @@
+/**
+ * @license
+ * Copyright 2020 Google LLC. 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 {Identity, IdentityInputs, KernelFunc, registerKernel} from '@tensorflow/tfjs-core';
+import {TensorInfo} from '@tensorflow/tfjs-core';
+
+import {BackendWasm} from '../backend_wasm';
+
+export function identity(args: {inputs: IdentityInputs, backend: BackendWasm}):
+    TensorInfo {
+  const {inputs: {x}, backend} = args;
+  const out = backend.makeOutput(x.shape, x.dtype);
+  const inVals = backend.typedArrayFromHeap(x);
+  const outVals = backend.typedArrayFromHeap(out);
+  outVals.set(inVals);
+  return out;
+}
+
+registerKernel({
+  kernelName: Identity,
+  backendName: 'wasm',
+  kernelFunc: identity as {} as KernelFunc,
+});
diff --git a/tfjs-backend-wasm/src/kernels/Reverse.ts b/tfjs-backend-wasm/src/kernels/Reverse.ts
index 6e2ed89c749..836ac304cb4 100644
--- a/tfjs-backend-wasm/src/kernels/Reverse.ts
+++ b/tfjs-backend-wasm/src/kernels/Reverse.ts
@@ -19,6 +19,7 @@ import {KernelConfig, KernelFunc, Reverse, ReverseAttrs, ReverseInputs, TensorIn
 
 import {BackendWasm} from '../backend_wasm';
 
+import {identity} from './Identity';
 import {reshape} from './Reshape';
 
 let wasmReverse: (
@@ -46,7 +47,7 @@ export function reverse(
   const axes = util.parseAxisParam(dims, x.shape);
 
   if (x.shape.length === 0) {
-    return backend.clone(x);
+    return identity({inputs: {x}, backend});
   }
 
   const out = backend.makeOutput(x.shape, x.dtype);
diff --git a/tfjs-backend-wasm/src/kernels/all_kernels.ts b/tfjs-backend-wasm/src/kernels/all_kernels.ts
index 1f304465401..c8cea76c002 100644
--- a/tfjs-backend-wasm/src/kernels/all_kernels.ts
+++ b/tfjs-backend-wasm/src/kernels/all_kernels.ts
@@ -45,6 +45,7 @@ import './Gather';
 import './GatherNd';
 import './Greater';
 import './GreaterEqual';
+import './Identity';
 import './Less';
 import './LessEqual';
 import './Log';
diff --git a/tfjs-core/src/ops/clone.ts b/tfjs-core/src/ops/clone.ts
index 4cffbd9bae8..cfbd45003fe 100644
--- a/tfjs-core/src/ops/clone.ts
+++ b/tfjs-core/src/ops/clone.ts
@@ -16,9 +16,9 @@
  */
 
 import {ENGINE} from '../engine';
-import {Identity} from '../kernel_names';
-
+import {Identity, IdentityInputs} from '../kernel_names';
 import {Tensor} from '../tensor';
+import {NamedTensorMap} from '../tensor_types';
 import {convertToTensor} from '../tensor_util_env';
 import {TensorLike} from '../types';
 
@@ -42,9 +42,12 @@ function clone_<T extends Tensor>(x: T|TensorLike): T {
   const forward = () =>
       ENGINE.makeTensorFromDataId($x.dataId, $x.shape, $x.dtype) as T;
 
+  const inputs: IdentityInputs = {x: $x};
+
   // Note this op is called tf.identity in python. Hence the kernel name used
   // here.
-  return ENGINE.runKernelFunc(forward, {x: $x}, null /* grad */, Identity);
+  return ENGINE.runKernelFunc(
+      forward, inputs as {} as NamedTensorMap, null /* grad */, Identity);
 }
 
 export const clone = op({clone_});