[CustomOps] TensorRT Gather Topk Ops (#1033)

* add gather topk * add shape inference and document * fix faster rcnn * reshape topk * fix
2025-01-14 08:09:43 +08:00 · 2022-09-19 13:48:26 +08:00 · 2022-09-19 13:48:26 +08:00 · 0caeaf238c
commit 0caeaf238c
parent 50bd6b1703
11 changed files with 476 additions and 20 deletions
--- a/csrc/mmdeploy/backend_ops/tensorrt/gather_topk/gather_topk.cpp
+++ b/csrc/mmdeploy/backend_ops/tensorrt/gather_topk/gather_topk.cpp
@ -0,0 +1,150 @@
+// Copyright (c) OpenMMLab. All rights reserved.
+#include "gather_topk.hpp"
+
+#include <assert.h>
+#include <stdio.h>
+
+#include <chrono>
+
+#include "NvInferVersion.h"
+#include "gather_topk_kernel.hpp"
+#include "trt_serialize.hpp"
+
+namespace mmdeploy {
+namespace {
+static const char *PLUGIN_VERSION{"1"};
+static const char *PLUGIN_NAME{"GatherTopk"};
+}  // namespace
+
+GatherTopk::GatherTopk(const std::string &name) : TRTPluginBase(name) {}
+
+GatherTopk::GatherTopk(const std::string name, const void *data, size_t length)
+    : TRTPluginBase(name) {}
+
+nvinfer1::IPluginV2DynamicExt *GatherTopk::clone() const TRT_NOEXCEPT {
+  GatherTopk *plugin = new GatherTopk(mLayerName);
+  plugin->setPluginNamespace(getPluginNamespace());
+
+  return plugin;
+}
+
+nvinfer1::DimsExprs GatherTopk::getOutputDimensions(
+    int outputIndex, const nvinfer1::DimsExprs *inputs, int nbInputs,
+    nvinfer1::IExprBuilder &exprBuilder) TRT_NOEXCEPT {
+  assert(inputs[0].nbDims >= inputs[1].nbDims);
+  nvinfer1::DimsExprs ret;
+  ret.nbDims = inputs[0].nbDims;
+  for (int i = 0; i < inputs[1].nbDims; ++i) {
+    ret.d[i] = inputs[1].d[i];
+  }
+  for (int i = inputs[1].nbDims; i < inputs[0].nbDims; ++i) {
+    ret.d[i] = inputs[0].d[i];
+  }
+  return ret;
+}
+
+bool GatherTopk::supportsFormatCombination(int pos, const nvinfer1::PluginTensorDesc *ioDesc,
+                                           int nbInputs, int nbOutputs) TRT_NOEXCEPT {
+  switch (pos) {
+    case 0:
+      // data
+      return (ioDesc[pos].type == nvinfer1::DataType::kFLOAT &&
+              ioDesc[pos].format == nvinfer1::TensorFormat::kLINEAR) ||
+             (ioDesc[pos].type == nvinfer1::DataType::kINT32 &&
+              ioDesc[pos].format == nvinfer1::TensorFormat::kLINEAR);
+    case 1:
+      // indices
+      return ioDesc[pos].type == nvinfer1::DataType::kINT32 &&
+             ioDesc[pos].format == nvinfer1::TensorFormat::kLINEAR;
+    case 2:
+      // output
+      return ioDesc[pos].type == ioDesc[0].type && ioDesc[pos].format == ioDesc[0].format;
+    default:
+      return true;
+  }
+  return true;
+}
+
+void GatherTopk::configurePlugin(const nvinfer1::DynamicPluginTensorDesc *inputs, int nbInputs,
+                                 const nvinfer1::DynamicPluginTensorDesc *outputs,
+                                 int nbOutputs) TRT_NOEXCEPT {}
+
+size_t GatherTopk::getWorkspaceSize(const nvinfer1::PluginTensorDesc *inputs, int nbInputs,
+                                    const nvinfer1::PluginTensorDesc *outputs,
+                                    int nbOutputs) const TRT_NOEXCEPT {
+  return 0;
+}
+
+int GatherTopk::enqueue(const nvinfer1::PluginTensorDesc *inputDesc,
+                        const nvinfer1::PluginTensorDesc *outputDesc, const void *const *inputs,
+                        void *const *outputs, void *workSpace, cudaStream_t stream) TRT_NOEXCEPT {
+  const int *dims = &(inputDesc[0].dims.d[0]);
+  const int *indices_dims = &(inputDesc[1].dims.d[0]);
+  int nbDims = inputDesc[0].dims.nbDims;
+  int indice_nbDims = inputDesc[1].dims.nbDims;
+
+  const void *data = inputs[0];
+  const void *indices = inputs[1];
+  void *output = outputs[0];
+
+  auto data_type = inputDesc[0].type;
+
+  switch (data_type) {
+    case nvinfer1::DataType::kFLOAT:
+      gather_topk_impl<float>((float *)data, (int *)indices, dims, nbDims, indices_dims,
+                              indice_nbDims, (float *)output, stream);
+      break;
+
+    case nvinfer1::DataType::kINT32:
+      gather_topk_impl<int>((int *)data, (int *)indices, dims, nbDims, indices_dims, indice_nbDims,
+                            (int *)output, stream);
+      break;
+    default:
+      break;
+  }
+
+  return 0;
+}
+
+nvinfer1::DataType GatherTopk::getOutputDataType(int index, const nvinfer1::DataType *inputTypes,
+                                                 int nbInputs) const TRT_NOEXCEPT {
+  return inputTypes[0];
+}
+
+// IPluginV2 Methods
+const char *GatherTopk::getPluginType() const TRT_NOEXCEPT { return PLUGIN_NAME; }
+
+const char *GatherTopk::getPluginVersion() const TRT_NOEXCEPT { return PLUGIN_VERSION; }
+
+int GatherTopk::getNbOutputs() const TRT_NOEXCEPT { return 1; }
+
+size_t GatherTopk::getSerializationSize() const TRT_NOEXCEPT { return 0; }
+
+void GatherTopk::serialize(void *buffer) const TRT_NOEXCEPT {}
+
+GatherTopkCreator::GatherTopkCreator() {
+  mPluginAttributes.clear();
+  mFC.nbFields = mPluginAttributes.size();
+  mFC.fields = mPluginAttributes.data();
+}
+
+const char *GatherTopkCreator::getPluginName() const TRT_NOEXCEPT { return PLUGIN_NAME; }
+
+const char *GatherTopkCreator::getPluginVersion() const TRT_NOEXCEPT { return PLUGIN_VERSION; }
+
+nvinfer1::IPluginV2 *GatherTopkCreator::createPlugin(
+    const char *name, const nvinfer1::PluginFieldCollection *fc) TRT_NOEXCEPT {
+  auto *plugin = new GatherTopk(name);
+  plugin->setPluginNamespace(getPluginNamespace());
+  return plugin;
+}
+
+nvinfer1::IPluginV2 *GatherTopkCreator::deserializePlugin(const char *name, const void *serialData,
+                                                          size_t serialLength) TRT_NOEXCEPT {
+  auto plugin = new GatherTopk(name, serialData, serialLength);
+  plugin->setPluginNamespace(getPluginNamespace());
+  return plugin;
+}
+
+REGISTER_TENSORRT_PLUGIN(GatherTopkCreator);
+}  // namespace mmdeploy
--- a/csrc/mmdeploy/backend_ops/tensorrt/gather_topk/gather_topk.hpp
+++ b/csrc/mmdeploy/backend_ops/tensorrt/gather_topk/gather_topk.hpp
@ -0,0 +1,64 @@
+// Copyright (c) OpenMMLab. All rights reserved.
+#ifndef TRT_SCATTERND_HPP
+#define TRT_SCATTERND_HPP
+#include <cublas_v2.h>
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "trt_plugin_base.hpp"
+
+namespace mmdeploy {
+class GatherTopk : public TRTPluginBase {
+ public:
+  GatherTopk(const std::string &name);
+
+  GatherTopk(const std::string name, const void *data, size_t length);
+
+  GatherTopk() = delete;
+
+  // IPluginV2DynamicExt Methods
+  nvinfer1::IPluginV2DynamicExt *clone() const TRT_NOEXCEPT override;
+  nvinfer1::DimsExprs getOutputDimensions(int outputIndex, const nvinfer1::DimsExprs *inputs,
+                                          int nbInputs, nvinfer1::IExprBuilder &exprBuilder)
+      TRT_NOEXCEPT override;
+  bool supportsFormatCombination(int pos, const nvinfer1::PluginTensorDesc *ioDesc, int nbInputs,
+                                 int nbOutputs) TRT_NOEXCEPT override;
+  void configurePlugin(const nvinfer1::DynamicPluginTensorDesc *in, int nbInputs,
+                       const nvinfer1::DynamicPluginTensorDesc *out,
+                       int nbOutputs) TRT_NOEXCEPT override;
+  size_t getWorkspaceSize(const nvinfer1::PluginTensorDesc *inputs, int nbInputs,
+                          const nvinfer1::PluginTensorDesc *outputs,
+                          int nbOutputs) const TRT_NOEXCEPT override;
+  int enqueue(const nvinfer1::PluginTensorDesc *inputDesc,
+              const nvinfer1::PluginTensorDesc *outputDesc, const void *const *inputs,
+              void *const *outputs, void *workspace, cudaStream_t stream) TRT_NOEXCEPT override;
+
+  // IPluginV2Ext Methods
+  nvinfer1::DataType getOutputDataType(int index, const nvinfer1::DataType *inputTypes,
+                                       int nbInputs) const TRT_NOEXCEPT override;
+
+  // IPluginV2 Methods
+  const char *getPluginType() const TRT_NOEXCEPT override;
+  const char *getPluginVersion() const TRT_NOEXCEPT override;
+  int getNbOutputs() const TRT_NOEXCEPT override;
+  size_t getSerializationSize() const TRT_NOEXCEPT override;
+  void serialize(void *buffer) const TRT_NOEXCEPT override;
+};
+
+class GatherTopkCreator : public TRTPluginCreatorBase {
+ public:
+  GatherTopkCreator();
+
+  const char *getPluginName() const TRT_NOEXCEPT override;
+
+  const char *getPluginVersion() const TRT_NOEXCEPT override;
+  nvinfer1::IPluginV2 *createPlugin(const char *name, const nvinfer1::PluginFieldCollection *fc)
+      TRT_NOEXCEPT override;
+
+  nvinfer1::IPluginV2 *deserializePlugin(const char *name, const void *serialData,
+                                         size_t serialLength) TRT_NOEXCEPT override;
+};
+}  // namespace mmdeploy
+#endif  // TRT_SCATTERND_HPP
--- a/csrc/mmdeploy/backend_ops/tensorrt/gather_topk/gather_topk_kernel.cu
+++ b/csrc/mmdeploy/backend_ops/tensorrt/gather_topk/gather_topk_kernel.cu
@ -0,0 +1,46 @@
+// Copyright (c) OpenMMLab. All rights reserved.
+
+#include <functional>
+#include <numeric>
+#include <vector>
+
+#include "common_cuda_helper.hpp"
+#include "gather_topk_kernel.hpp"
+#include "trt_plugin_helper.hpp"
+
+template <typename scalar_t>
+__global__ void gather_topk_kernel(const scalar_t* input, const int* indices, scalar_t* output,
+                                   int batch, int num_input, int num_indices, int channel) {
+  CUDA_1D_KERNEL_LOOP(index, batch * num_indices * channel) {
+    const int b_id = index / (num_indices * channel);
+    const int n_id = (index / channel) % num_indices;
+    const int c_id = index % channel;
+
+    const int input_n_id = indices[b_id * num_indices + n_id];
+    const scalar_t value = input[b_id * num_input * channel + input_n_id * channel + c_id];
+    output[b_id * num_indices * channel + n_id * channel + c_id] = value;
+  }
+}
+
+template <typename scalar_t>
+void gather_topk_impl(const scalar_t* input, const int* indices, const int* dims, int nbDims,
+                      const int* indices_dims, int indice_nbDims, scalar_t* output,
+                      cudaStream_t stream) {
+  int batch = 1;
+  for (int i = 0; i < indice_nbDims - 1; ++i) batch *= dims[i];
+  int num_input = dims[indice_nbDims - 1];
+  int num_indices = indices_dims[indice_nbDims - 1];
+  int channel = 1;
+  for (int i = indice_nbDims; i < nbDims; ++i) channel *= dims[i];
+  const int col_block = DIVUP(batch * num_indices * channel, THREADS_PER_BLOCK);
+  gather_topk_kernel<<<col_block, THREADS_PER_BLOCK, 0, stream>>>(input, indices, output, batch,
+                                                                  num_input, num_indices, channel);
+}
+
+template void gather_topk_impl<float>(const float* input, const int* indices, const int* dims,
+                                      int nbDims, const int* indices_dims, int indice_nbDims,
+                                      float* output, cudaStream_t stream);
+
+template void gather_topk_impl<int32_t>(const int32_t* input, const int* indices, const int* dims,
+                                        int nbDims, const int* indices_dims, int indice_nbDims,
+                                        int32_t* output, cudaStream_t stream);
--- a/csrc/mmdeploy/backend_ops/tensorrt/gather_topk/gather_topk_kernel.hpp
+++ b/csrc/mmdeploy/backend_ops/tensorrt/gather_topk/gather_topk_kernel.hpp
@ -0,0 +1,10 @@
+// Copyright (c) OpenMMLab. All rights reserved.
+#ifndef TRT_GRID_SAMPLER_KERNEL_HPP
+#define TRT_GRID_SAMPLER_KERNEL_HPP
+#include <cuda_runtime.h>
+
+template <typename scalar_t>
+void gather_topk_impl(const scalar_t* input, const int* indices, const int* dims, int nbDims,
+                      const int* indices_dims, int indice_nbDims, scalar_t* output,
+                      cudaStream_t stream);
+#endif  // TRT_GRID_SAMPLER_KERNEL_HPP
--- a/docs/en/06-custom-ops/tensorrt.md
+++ b/docs/en/06-custom-ops/tensorrt.md
@ -63,6 +63,12 @@
    - [Inputs](#inputs-9)
    - [Outputs](#outputs-9)
    - [Type Constraints](#type-constraints-9)
+  - [GatherTopk](#gathertopk)
+    - [Description](#description-10)
+    - [Parameters](#parameters-10)
+    - [Inputs](#inputs-10)
+    - [Outputs](#outputs-10)
+    - [Type Constraints](#type-constraints-10)

 <!-- TOC -->

@ -447,3 +453,39 @@ None
 #### Type Constraints

 - T:tensor(float32, Linear)
+
+### GatherTopk
+
+#### Description
+
+TensorRT 8.2~8.4 would give unexpected result for multi-index gather.
+
+```python
+data[batch_index, bbox_index, ...]
+```
+
+Read [this](https://github.com/NVIDIA/TensorRT/issues/2299) for more details.
+
+#### Parameters
+
+None
+
+#### Inputs
+
+<dl>
+<dt><tt>inputs[0]</tt>: T</dt>
+<dd>Tensor to be gathered, with shape (A0, ..., An, G0, C0, ...).</dd>
+
+<dt><tt>inputs[1]</tt>: tensor(int32, Linear)</dt>
+<dd>Tensor of index. with shape (A0, ..., An, G1)</dd>
+
+#### Outputs
+
+<dl>
+<dt><tt>outputs[0]</tt>: T</dt>
+<dd>Tensor of output. With shape (A0, ..., An, G1, C0, ...)</dd>
+</dl>
+
+#### Type Constraints
+
+- T:tensor(float32, Linear), tensor(int32, Linear)
--- a/docs/zh_cn/06-custom-ops/tensorrt.md
+++ b/docs/zh_cn/06-custom-ops/tensorrt.md
@ -63,6 +63,12 @@
    - [Inputs](#inputs-9)
    - [Outputs](#outputs-9)
    - [Type Constraints](#type-constraints-9)
+  - [GatherTopk](#gathertopk)
+    - [Description](#description-10)
+    - [Parameters](#parameters-10)
+    - [Inputs](#inputs-10)
+    - [Outputs](#outputs-10)
+    - [Type Constraints](#type-constraints-10)

 <!-- TOC -->

@ -447,3 +453,39 @@ None
 #### Type Constraints

 - T:tensor(float32, Linear)
+
+### GatherTopk
+
+#### Description
+
+TensorRT 8.2~8.4 would give unexpected result for multi-index gather.
+
+```python
+data[batch_index, bbox_index, ...]
+```
+
+Read [this](https://github.com/NVIDIA/TensorRT/issues/2299) for more details.
+
+#### Parameters
+
+None
+
+#### Inputs
+
+<dl>
+<dt><tt>inputs[0]</tt>: T</dt>
+<dd>Tensor to be gathered, with shape (A0, ..., An, G0, C0, ...).</dd>
+
+<dt><tt>inputs[1]</tt>: tensor(int32, Linear)</dt>
+<dd>Tensor of index. with shape (A0, ..., An, G1)</dd>
+
+#### Outputs
+
+<dl>
+<dt><tt>outputs[0]</tt>: T</dt>
+<dd>Tensor of output. With shape (A0, ..., An, G1, C0, ...)</dd>
+</dl>
+
+#### Type Constraints
+
+- T:tensor(float32, Linear), tensor(int32, Linear)
--- a/mmdeploy/codebase/mmdet/core/post_processing/bbox_nms.py
+++ b/mmdeploy/codebase/mmdet/core/post_processing/bbox_nms.py
@ -261,6 +261,13 @@ def multiclass_nms_static(ctx,
                                         pre_top_k, keep_top_k, iou_threshold,
                                         score_threshold, -1)

+    # retain shape info
+    batch_size = boxes.size(0)
+
+    dets_shape = dets.shape
+    label_shape = labels.shape
+    dets = dets.reshape([batch_size, *dets_shape[1:]])
+    labels = labels.reshape([batch_size, *label_shape[1:]])
    return dets, labels


--- a/mmdeploy/codebase/mmdet/deploy/utils.py
+++ b/mmdeploy/codebase/mmdet/deploy/utils.py
@ -200,6 +200,53 @@ def __gather_topk(*inputs: Sequence[torch.Tensor],
    return outputs


+class TRTGatherTopk(torch.autograd.Function):
+
+    @staticmethod
+    def forward(ctx, x: torch.Tensor, inds: torch.Tensor):
+        """Implement of gather topk."""
+        batch_size = x.size(0)
+        batch_inds = torch.arange(batch_size, device=inds.device).unsqueeze(-1)
+        return x[batch_inds, inds, ...]
+
+    @staticmethod
+    def symbolic(g, x, inds):
+        """symbolic of gather topk."""
+        out = g.op('mmdeploy::GatherTopk', x, inds, outputs=1)
+
+        return out
+
+
+@FUNCTION_REWRITER.register_rewriter(
+    'mmdeploy.codebase.mmdet.deploy.utils.__gather_topk',
+    backend=Backend.TENSORRT.value)
+def __gather_topk__trt(ctx,
+                       *inputs: Sequence[torch.Tensor],
+                       inds: torch.Tensor,
+                       batch_size: int,
+                       is_batched: bool = True) -> Tuple[torch.Tensor]:
+    """TensorRT gather_topk."""
+    _ = ctx
+    if is_batched:
+        index_shape = inds.shape
+        index_dim = inds.dim()
+        outputs = [None for _ in inputs]
+        for i, x in enumerate(inputs):
+            if x is None:
+                continue
+            out = TRTGatherTopk.apply(x, inds).to(x.dtype)
+            out_shape = [*index_shape, *x.shape[index_dim:]]
+            out = out.reshape(out_shape)
+            outputs[i] = out
+    else:
+        prior_inds = inds.new_zeros((1, 1))
+        outputs = [
+            x[prior_inds, inds, ...] if x is not None else None for x in inputs
+        ]
+
+    return outputs
+
+
@FUNCTION_REWRITER.register_rewriter(
    'mmdeploy.codebase.mmdet.deploy.utils.__gather_topk',
    backend=Backend.COREML.value)
--- a/mmdeploy/codebase/mmdet/models/dense_heads/gfl_head.py
+++ b/mmdeploy/codebase/mmdet/models/dense_heads/gfl_head.py
@ -2,7 +2,7 @@
 import torch
 import torch.nn.functional as F

-from mmdeploy.codebase.mmdet import (get_post_processing_params,
+from mmdeploy.codebase.mmdet import (gather_topk, get_post_processing_params,
                                     multiclass_nms, pad_with_value)
 from mmdeploy.core import FUNCTION_REWRITER
 from mmdeploy.utils import Backend, get_backend, is_dynamic_shape
@ -129,14 +129,18 @@ def gfl_head__get_bbox(ctx,
            else:
                max_scores, _ = nms_pre_score[..., :-1].max(-1)
            _, topk_inds = max_scores.topk(pre_topk)
-            batch_inds = torch.arange(
-                batch_size, device=bbox_pred.device).unsqueeze(-1)
-            prior_inds = batch_inds.new_zeros((1, 1))
-            priors = priors[prior_inds, topk_inds, :]
-            bbox_pred = bbox_pred[batch_inds, topk_inds, :]
-            scores = scores[batch_inds, topk_inds, :]
-            if with_score_factors:
-                score_factors = score_factors[batch_inds, topk_inds, :]
+            bbox_pred, scores, score_factors = gather_topk(
+                bbox_pred,
+                scores,
+                score_factors,
+                inds=topk_inds,
+                batch_size=batch_size,
+                is_batched=True)
+            priors = gather_topk(
+                priors,
+                inds=topk_inds,
+                batch_size=batch_size,
+                is_batched=False)

        mlvl_valid_bboxes.append(bbox_pred)
        mlvl_valid_scores.append(scores)
--- a/mmdeploy/codebase/mmdet/models/dense_heads/reppoints_head.py
+++ b/mmdeploy/codebase/mmdet/models/dense_heads/reppoints_head.py
@ -3,7 +3,7 @@ from typing import Sequence

 import torch

-from mmdeploy.codebase.mmdet import (get_post_processing_params,
+from mmdeploy.codebase.mmdet import (gather_topk, get_post_processing_params,
                                     multiclass_nms,
                                     pad_with_value_if_necessary)
 from mmdeploy.core import FUNCTION_REWRITER
@ -37,11 +37,14 @@ def reppoints_head__points2bbox(ctx, self, pts, y_first=True):
    Use `self.moment_transfer` in `points2bbox` will cause error:
    RuntimeError: Input, output and indices must be on the current device
    """
-    moment_transfer = self.moment_transfer
-    delattr(self, 'moment_transfer')
-    self.moment_transfer = torch.tensor(moment_transfer.data)
+    update_moment = hasattr(self, 'moment_transfer')
+    if update_moment:
+        moment_transfer = self.moment_transfer
+        delattr(self, 'moment_transfer')
+        self.moment_transfer = torch.tensor(moment_transfer.data)
    ret = ctx.origin_func(self, pts, y_first=y_first)
-    self.moment_transfer = moment_transfer
+    if update_moment:
+        self.moment_transfer = moment_transfer
    return ret


@ -131,12 +134,17 @@ def reppoints_head__get_bboxes(ctx,
            else:
                max_scores, _ = nms_pre_score[..., :-1].max(-1)
            _, topk_inds = max_scores.topk(pre_topk)
-            batch_inds = torch.arange(
-                batch_size, device=bbox_pred.device).unsqueeze(-1)
-            prior_inds = batch_inds.new_zeros((1, 1))
-            priors = priors[prior_inds, topk_inds, :]
-            bbox_pred = bbox_pred[batch_inds, topk_inds, :]
-            scores = scores[batch_inds, topk_inds, :]
+            bbox_pred, scores = gather_topk(
+                bbox_pred,
+                scores,
+                inds=topk_inds,
+                batch_size=batch_size,
+                is_batched=True)
+            priors = gather_topk(
+                priors,
+                inds=topk_inds,
+                batch_size=batch_size,
+                is_batched=False)

        bbox_pred = _bbox_pre_decode(priors, bbox_pred,
                                     self.point_strides[level_idx])
--- a/tests/test_ops/test_ops.py
+++ b/tests/test_ops/test_ops.py
@ -1124,3 +1124,39 @@ def test_dot_product_attention(backend, save_dir=None):
            input_names=['query', 'key', 'value'],
            output_names=['out', 'attn'],
            save_dir=save_dir)
+
+
+@pytest.mark.parametrize('backend', [TEST_TENSORRT])
+def test_gather_topk(backend, save_dir=None):
+    backend.check_env()
+    from mmdeploy.codebase.mmdet.deploy.utils import gather_topk
+
+    x = torch.rand(2, 10, 4).cuda()
+
+    class TestModel(torch.nn.Module):
+
+        def __init__(self) -> None:
+            super().__init__()
+
+        def forward(self, x):
+            batch_size = x.size(0)
+            max_x, _ = x.max(-1)
+            _, inds = max_x.topk(4)
+
+            new_x = gather_topk(x, inds=inds, batch_size=batch_size)
+            return new_x
+
+    model = TestModel().cuda()
+
+    with RewriterContext(
+            Config({'backend_config': {
+                'type': backend.backend_name
+            }}),
+            backend=backend.backend_name,
+            opset=11):
+        backend.run_and_validate(
+            model, [x],
+            'gather_topk',
+            input_names=['x'],
+            output_names=['out'],
+            save_dir=save_dir)