Support beam search decode op in XPU environment (#44917)

* support beam_search operator on xpu. test=kunlun

* support beam_search operator on xpu. test=kunlun

* support beam_search operator on xpu. test=kunlun

* support beam_search operator on xpu. test=kunlun

* support beam_search operator on xpu. test=kunlun

* support beam_search operator on xpu. test=kunlun

* support beam_search operator on xpu. test=kunlun

* fix beam_search operator bugs on xpu. test=kunlun

* fix beam_search operator bugs on xpu. test=kunlun

* fix beam_search operator bugs on xpu. test=kunlun

* fix beam_search operator bugs on xpu. test=kunlun

* support beam_search_decode operator on xpu. test=kunlun

* support beam_search_decode operator on xpu. test=kunlun

* support beam_search_decode operator on xpu. test=kunlun

* support beam_search_decode operator on xpu. test=kunlun

* support beam_search_decode operator on xpu. test=kunlun

* support beam_search_decode operator on xpu. test=kunlun

* support beam_search_decode operator on xpu. test=kunlun

* support beam_search_decode operator on xpu. test=kunlun

* support beam_search_decode operator on xpu. test=kunlun

* support beam_search_decode operator on xpu. test=kunlun

* support beam_search_decode operator on xpu. test=kunlun

* support beam_search_decode operator on xpu. test=kunlun

* support beam_search_decode operator on xpu. test=kunlun

* support beam_search_decode operator on xpu. test=kunlun

* support beam_search_decode operator on xpu. test=kunlun

paddle/fluid/operators/CMakeLists.txt

@@ -163,6 +163,7 @@ if (WITH_GPU OR WITH_ROCM)
   set(COMMON_OP_DEPS ${COMMON_OP_DEPS} depthwise_conv prelu bert_encoder_functor)
 endif()
 if(WITH_XPU)
+  cc_test(beam_search_decode_op_xpu_test SRCS beam_search_decode_op_xpu_test.cc DEPS lod_tensor)
   set(COMMON_OP_DEPS ${COMMON_OP_DEPS} xpulib)
 endif()
 set(COMMON_OP_DEPS ${COMMON_OP_DEPS} device_memory_aligment)

paddle/fluid/operators/beam_search_decode_op.cc

@@ -13,195 +13,24 @@ See the License for the specific language governing permissions and
 limitations under the License. */
 
 #include "paddle/fluid/operators/beam_search_decode_op.h"
-
 #include <string>
-
-#include "paddle/fluid/framework/convert_utils.h"
-#include "paddle/fluid/platform/device_context.h"
-
-namespace paddle {
-namespace framework {
-class InferShapeContext;
-class OpDesc;
-class Scope;
-template <typename T>
-class EmptyGradOpMaker;
-}  // namespace framework
-namespace imperative {
-class OpBase;
-}  // namespace imperative
-}  // namespace paddle
+#include "paddle/fluid/framework/op_registry.h"
 
 namespace paddle {
 namespace operators {
 
-struct BeamSearchDecodeFunctor {
-  BeamSearchDecodeFunctor(const LoDTensorArray& step_ids,
-                          const LoDTensorArray& step_scores,
-                          LoDTensor* id_tensor,
-                          LoDTensor* score_tensor,
-                          size_t beam_size,
-                          int end_id)
-      : beam_size_(beam_size),
-        end_id_(end_id),
-        step_ids_origin_(step_ids),
-        step_scores_origin_(step_scores),
-        id_tensor_(id_tensor),
-        score_tensor_(score_tensor) {
-    tensor_on_gpu_ = false;
-    tensor_on_npu_ = false;
-    // First make a copy of GPU data on CPU
-    if (platform::is_gpu_place(step_ids_origin_[0].place()) ||
-        platform::is_npu_place(step_ids_origin_[0].place())) {
-      if (platform::is_gpu_place(step_ids_origin_[0].place())) {
-        tensor_on_gpu_ = true;
-      } else {
-        tensor_on_npu_ = true;
-      }
-      platform::DeviceContextPool& pool =
-          platform::DeviceContextPool::Instance();
-      auto* dev_ctx = pool.Get(step_ids_origin_[0].place());
-      // Copy all tensors in the input tensor array
-      for (auto& step_id : step_ids_origin_) {
-        framework::LoDTensor out;
-        if (step_id.numel() > 0) {
-          if (tensor_on_gpu_) {
-            dev_ctx->Wait();
-          }
-          framework::TensorCopy(step_id, platform::CPUPlace(), *dev_ctx, &out);
-          dev_ctx->Wait();
-        }
-
-        out.set_lod(step_id.lod());
-        step_ids_.push_back(out);
-      }
-    }
-    if (platform::is_gpu_place(step_scores_origin_[0].place()) ||
-        platform::is_npu_place(step_scores_origin_[0].place())) {
-      if (platform::is_gpu_place(step_scores_origin_[0].place())) {
-        tensor_on_gpu_ = true;
-      } else {
-        tensor_on_npu_ = true;
-      }
-      platform::DeviceContextPool& pool =
-          platform::DeviceContextPool::Instance();
-      auto* dev_ctx = pool.Get(step_scores_origin_[0].place());
-      // Copy all tensors in the input tensor array
-      for (auto& step_score : step_scores_origin_) {
-        framework::LoDTensor out;
-        if (step_score.numel() > 0) {
-          if (tensor_on_gpu_) {
-            dev_ctx->Wait();
-          }
-          framework::TensorCopy(
-              step_score, platform::CPUPlace(), *dev_ctx, &out);
-          dev_ctx->Wait();
-        }
-
-        out.set_lod(step_score.lod());
-        step_scores_.push_back(out);
-      }
-    }
-  }
-
-  template <typename T>
-  void apply() const;
-
-  bool tensor_on_gpu_;
-  bool tensor_on_npu_;
-  size_t beam_size_;
-  int end_id_;
-  // TODO(Superjomn) Here might result serious performance issue in the
-  // concurrency
-  // scenarios.
-  const LoDTensorArray& step_ids_origin_;
-  const LoDTensorArray& step_scores_origin_;
-  LoDTensorArray step_ids_ = LoDTensorArray();
-  LoDTensorArray step_scores_ = LoDTensorArray();
-  LoDTensor* id_tensor_;
-  LoDTensor* score_tensor_;
-};
-
-template <typename T>
-void BeamSearchDecodeFunctor::apply() const {
-  BeamSearchDecoder<T> beam_search_decoder(beam_size_, end_id_);
-  // Check if the tensor is on GPU or NPU. If so, use the CPU copy instead
-  if (tensor_on_gpu_ || tensor_on_npu_) {
-    beam_search_decoder.Backtrace(
-        step_ids_, step_scores_, id_tensor_, score_tensor_);
-  } else {
-    beam_search_decoder.Backtrace(
-        step_ids_origin_, step_scores_origin_, id_tensor_, score_tensor_);
-  }
-}
-
-template <>
-void BeamSearchDecodeFunctor::apply<bool>() const {
-  PADDLE_THROW(platform::errors::InvalidArgument(
-      "beam search decode op does not support bool!"));
-}
-
-class BeamSearchDecodeOp : public framework::OperatorBase {
+class BeamSearchDecodeOp : public framework::OperatorWithKernel {
  public:
-  BeamSearchDecodeOp(const std::string& type,
-                     const framework::VariableNameMap& inputs,
-                     const framework::VariableNameMap& outputs,
-                     const framework::AttributeMap& attrs)
-      : OperatorBase(type, inputs, outputs, attrs) {}
-
- private:
-  void RunImpl(const framework::Scope& scope,
-               const platform::Place& dev_place) const override {
-    platform::DeviceContextPool& pool = platform::DeviceContextPool::Instance();
-    auto& dev_ctx = *pool.Get(dev_place);
-
-    framework::RuntimeContext run_ctx(Inputs(), Outputs(), scope);
-    framework::ExecutionContext ctx(*this, scope, dev_ctx, run_ctx);
-
-    const LoDTensorArray* ids = ctx.Input<LoDTensorArray>("Ids");
-    const LoDTensorArray* scores = ctx.Input<LoDTensorArray>("Scores");
-    const size_t step_num = ids->size();
-    PADDLE_ENFORCE_GT(
-        step_num,
-        0UL,
-        platform::errors::InvalidArgument(
-            "beam search steps, which is the"
-            "size of Input(Ids) LoDTensorArray. beam search steps should "
-            "be larger than 0, but received %d. ",
-            step_num));
-    const size_t source_num = ids->at(0).lod().at(0).size() - 1;
-    PADDLE_ENFORCE_GT(
-        source_num,
-        0UL,
-        platform::errors::InvalidArgument(
-            "source_num is the sequence number of the"
-            "first decoding step, indicating by Input(Ids)[0].lod[0].size. "
-            "The number of source_num should be larger than"
-            "0, but received %d. ",
-            source_num));
+  using framework::OperatorWithKernel::OperatorWithKernel;
 
-    for (size_t i = 0; i < step_num; ++i) {
-      PADDLE_ENFORCE_EQ(
-          ids->at(i).lod().size(),
-          2UL,
-          platform::errors::InvalidArgument(
-              "For the i step in beam search steps,"
-              "the size of Input(Ids)[i].lod() should larger than 2,"
-              "but received %d. ",
-              ids->at(i).lod().size()));
+  void InferShape(framework::InferShapeContext *ctx) const override {
+    for (const std::string &arg : std::vector<std::string>({"Ids", "Scores"})) {
+      OP_INOUT_CHECK(ctx->HasInput(arg), "Input", arg, "BeamSeachDecode");
+    }
+    for (const std::string &arg :
+         std::vector<std::string>({"SentenceIds", "SentenceScores"})) {
+      OP_INOUT_CHECK(ctx->HasOutput(arg), "Output", arg, "BeamSeachDecode");
     }
-
-    size_t beam_size = ctx.Attr<int>("beam_size");
-    int end_id = ctx.Attr<int>("end_id");
-
-    // prepare output
-    LoDTensor* sentenceIds = ctx.Output<LoDTensor>("SentenceIds");
-    LoDTensor* sentenceScores = ctx.Output<LoDTensor>("SentenceScores");
-
-    framework::VisitDataType(
-        framework::TransToProtoVarType(scores->at(0).dtype()),
-        BeamSearchDecodeFunctor(
-            *ids, *scores, sentenceIds, sentenceScores, beam_size, end_id));
   }
 };
 
@@ -240,7 +69,7 @@ hypothesis has.
   }
 };
 
-class BeamSearchDecodeInferShape : public framework::InferShapeBase {
+/*class BeamSearchDecodeInferShape : public framework::InferShapeBase {
  public:
   void operator()(framework::InferShapeContext* context) const override {
     OP_INOUT_CHECK(
@@ -256,11 +85,11 @@ class BeamSearchDecodeInferShape : public framework::InferShapeBase {
                    "SentenceScores",
                    "BeamSearchDecode");
   }
-};
+};*/
 
 class BeamSearchDecodeInferVarType : public framework::VarTypeInference {
  public:
-  void operator()(framework::InferVarTypeContext* ctx) const override {
+  void operator()(framework::InferVarTypeContext *ctx) const override {
     ctx->SetOutputType("SentenceIds",
                        framework::proto::VarType::LOD_TENSOR,
                        framework::ALL_ELEMENTS);
@@ -273,11 +102,16 @@ class BeamSearchDecodeInferVarType : public framework::VarTypeInference {
 }  // namespace operators
 }  // namespace paddle
 
-REGISTER_OPERATOR(
+namespace ops = paddle::operators;
+REGISTER_OPERATOR(beam_search_decode,
+                  paddle::operators::BeamSearchDecodeOp,
+                  paddle::operators::BeamSearchDecodeOpProtoMaker,
+                  paddle::operators::BeamSearchDecodeInferVarType);
+
+REGISTER_OP_CPU_KERNEL(
     beam_search_decode,
-    paddle::operators::BeamSearchDecodeOp,
-    paddle::operators::BeamSearchDecodeOpProtoMaker,
-    paddle::operators::BeamSearchDecodeInferShape,
-    paddle::operators::BeamSearchDecodeInferVarType,
-    paddle::framework::EmptyGradOpMaker<paddle::framework::OpDesc>,
-    paddle::framework::EmptyGradOpMaker<paddle::imperative::OpBase>);
+    ops::BeamSearchDecodeOpKernel<phi::CPUContext, float>,
+    ops::BeamSearchDecodeOpKernel<phi::CPUContext, double>,
+    ops::BeamSearchDecodeOpKernel<phi::CPUContext, paddle::platform::float16>,
+    ops::BeamSearchDecodeOpKernel<phi::CPUContext, int>,
+    ops::BeamSearchDecodeOpKernel<phi::CPUContext, int64_t>);

paddle/fluid/operators/beam_search_decode_op.cu.cc

+/* Copyright (c) 2016 PaddlePaddle 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 "paddle/fluid/operators/beam_search_decode_op.h"
+#include "paddle/fluid/framework/op_registry.h"
+
+namespace ops = paddle::operators;
+REGISTER_OP_CUDA_KERNEL(
+    beam_search_decode,
+    ops::BeamSearchDecodeOpKernel<phi::GPUContext, float>,
+    ops::BeamSearchDecodeOpKernel<phi::GPUContext, double>,
+    ops::BeamSearchDecodeOpKernel<phi::GPUContext, paddle::platform::float16>,
+    ops::BeamSearchDecodeOpKernel<phi::GPUContext, int>,
+    ops::BeamSearchDecodeOpKernel<phi::GPUContext, int64_t>);

paddle/fluid/operators/beam_search_decode_op.h

@@ -14,231 +14,164 @@ limitations under the License. */
 
 #pragma once
 
-#include <algorithm>
-#include <memory>
-#include <vector>
-
-#include "paddle/fluid/framework/lod_tensor.h"
-#include "paddle/fluid/framework/lod_tensor_array.h"
-#include "paddle/fluid/framework/op_registry.h"
-#include "paddle/fluid/platform/enforce.h"
+#include "paddle/fluid/framework/operator.h"
+#include "paddle/fluid/operators/beam_search_decode_op_def.h"
 
 namespace paddle {
 namespace operators {
 
-using LoDTensor = framework::LoDTensor;
-using LoDTensorArray = framework::LoDTensorArray;
+struct BeamSearchDecodeFunctor {
+  BeamSearchDecodeFunctor(const LoDTensorArray& step_ids,
+                          const LoDTensorArray& step_scores,
+                          LoDTensor* id_tensor,
+                          LoDTensor* score_tensor,
+                          size_t beam_size,
+                          int end_id)
+      : beam_size_(beam_size),
+        end_id_(end_id),
+        step_ids_origin_(step_ids),
+        step_scores_origin_(step_scores),
+        id_tensor_(id_tensor),
+        score_tensor_(score_tensor) {
+    tensor_on_gpu_ = false;
+    tensor_on_npu_ = false;
+    // First make a copy of GPU data on CPU
+    if (platform::is_gpu_place(step_ids_origin_[0].place()) ||
+        platform::is_npu_place(step_ids_origin_[0].place())) {
+      if (platform::is_gpu_place(step_ids_origin_[0].place())) {
+        tensor_on_gpu_ = true;
+      } else {
+        tensor_on_npu_ = true;
+      }
+      platform::DeviceContextPool& pool =
+          platform::DeviceContextPool::Instance();
+      auto* dev_ctx = pool.Get(step_ids_origin_[0].place());
+      // Copy all tensors in the input tensor array
+      for (auto& step_id : step_ids_origin_) {
+        framework::LoDTensor out;
+        if (step_id.numel() > 0) {
+          if (tensor_on_gpu_) {
+            dev_ctx->Wait();
+          }
+          framework::TensorCopy(step_id, platform::CPUPlace(), *dev_ctx, &out);
+          dev_ctx->Wait();
+        }
 
-// all the lod have 2 levels.
-// The first is source level, the second is sentence level.
-// source level describe how many prefixes (branchs) for each source sentece
-// (beam). sentence level describe how these candidates belong to the prefixes.
-const size_t kSourceLevel = 0;
-const size_t kSentenceLevel = 1;
+        out.set_lod(step_id.lod());
+        step_ids_.push_back(out);
+      }
+    }
+    if (platform::is_gpu_place(step_scores_origin_[0].place()) ||
+        platform::is_npu_place(step_scores_origin_[0].place())) {
+      if (platform::is_gpu_place(step_scores_origin_[0].place())) {
+        tensor_on_gpu_ = true;
+      } else {
+        tensor_on_npu_ = true;
+      }
+      platform::DeviceContextPool& pool =
+          platform::DeviceContextPool::Instance();
+      auto* dev_ctx = pool.Get(step_scores_origin_[0].place());
+      // Copy all tensors in the input tensor array
+      for (auto& step_score : step_scores_origin_) {
+        framework::LoDTensor out;
+        if (step_score.numel() > 0) {
+          if (tensor_on_gpu_) {
+            dev_ctx->Wait();
+          }
+          framework::TensorCopy(
+              step_score, platform::CPUPlace(), *dev_ctx, &out);
+          dev_ctx->Wait();
+        }
 
-template <typename T>
-struct Sentence {
-  std::vector<int64_t> word_ids;
-  std::vector<T> scores;
-};
+        out.set_lod(step_score.lod());
+        step_scores_.push_back(out);
+      }
+    }
+  }
 
-template <typename T>
-using SentenceVector = std::vector<Sentence<T>>;
-
-template <typename T>
-struct BeamSearchDecoder {
-  BeamSearchDecoder(size_t beam_size, int end_id)
-      : beam_size_(beam_size), end_id_(end_id) {}
-
-  /**
-   * convert the result sentence_vector for each source sentence into two
-   * LodTensor.
-   * One is all candidate sentences with word id, one is all candidate sentences
-   * with word score.
-   * Param:
-   *  sentence_vector_list: sentence_vector for each source sentence.
-   *  id_tensor: result LoDTensor for sentences of id.
-   *  score_tensor: result LoDTensor for sentences of score.
-   *  reverse: whether ids of sentence in sentence_vector_list is reversed
-   *  sort_by_score: whether to sort hypotheses of each sentence by scores.
-   */
-  void ConvertSentenceVectorToLodTensor(
-      std::vector<SentenceVector<T>> sentence_vector_list,
-      LoDTensor* id_tensor,
-      LoDTensor* score_tensor,
-      bool reverse = true,
-      bool sort_by_score = true) const;
-
-  /**
-   * Gather the hypotheses for each source sentence by backtrace though the
-   * LoDTensorArray step_ids whose lods reserve the path in the tree.
-   */
-  void Backtrace(const LoDTensorArray& step_ids,
-                 const LoDTensorArray& step_scores,
-                 LoDTensor* id_tensor,
-                 LoDTensor* score_tensor) const;
+  template <typename T>
+  void apply_mix() const {
+    if (std::is_same<bool, T>::value) {
+      PADDLE_THROW(platform::errors::InvalidArgument(
+          "beam search decode op does not support bool!"));
+
+    } else {
+      BeamSearchDecoder<T> beam_search_decoder(beam_size_, end_id_);
+      // Check if the tensor is on GPU or NPU. If so, use the CPU copy instead
+      if (tensor_on_gpu_ || tensor_on_npu_) {
+        beam_search_decoder.Backtrace(
+            step_ids_, step_scores_, id_tensor_, score_tensor_);
+      } else {
+        beam_search_decoder.Backtrace(
+            step_ids_origin_, step_scores_origin_, id_tensor_, score_tensor_);
+      }
+    }
+  }
 
+  bool tensor_on_gpu_;
+  bool tensor_on_npu_;
   size_t beam_size_;
   int end_id_;
+  // TODO(Superjomn) Here might result serious performance issue in the
+  // concurrency
+  // scenarios.
+  const LoDTensorArray& step_ids_origin_;
+  const LoDTensorArray& step_scores_origin_;
+  LoDTensorArray step_ids_ = LoDTensorArray();
+  LoDTensorArray step_scores_ = LoDTensorArray();
+  LoDTensor* id_tensor_;
+  LoDTensor* score_tensor_;
 };
 
-template <typename T>
-void BeamSearchDecoder<T>::ConvertSentenceVectorToLodTensor(
-    std::vector<SentenceVector<T>> sentence_vector_list,
-    LoDTensor* id_tensor,
-    LoDTensor* score_tensor,
-    bool reverse,
-    bool sort_by_score) const {
-  size_t src_num = sentence_vector_list.size();
-
-  PADDLE_ENFORCE_NE(
-      src_num,
-      0,
-      platform::errors::InvalidArgument(
-          "src_num is the sequence number of the first decoding step"
-          ", indicating by Input(Ids)[0].lod[0].size."
-          "src_num has wrong value."
-          "src_num should not be 0,"
-          "But received %d.",
-          src_num));
-
-  std::vector<size_t> source_level_lod = {0};
-  std::vector<size_t> sentence_level_lod = {0};
-  std::vector<int64_t> id_data;
-  std::vector<T> score_data;
-
-  for (size_t src_idx = 0; src_idx < src_num; ++src_idx) {
-    if (sort_by_score) {
-      sort(sentence_vector_list[src_idx].begin(),
-           sentence_vector_list[src_idx].end(),
-           [reverse](const Sentence<T>& a, const Sentence<T>& b) {
-             if (reverse)
-               return a.scores.front() > b.scores.front();
-             else
-               return a.scores.back() > b.scores.back();
-           });
+template <typename DeviceContext, typename T>
+class BeamSearchDecodeOpKernel : public framework::OpKernel<T> {
+ public:
+  void Compute(const framework::ExecutionContext& context) const override {
+    const LoDTensorArray* ids = context.Input<LoDTensorArray>("Ids");
+    const LoDTensorArray* scores = context.Input<LoDTensorArray>("Scores");
+    const size_t step_num = ids->size();
+    PADDLE_ENFORCE_GT(
+        step_num,
+        0UL,
+        platform::errors::InvalidArgument(
+            "beam search steps, which is the"
+            "size of Input(Ids) LoDTensorArray. beam search steps should "
+            "be larger than 0, but received %d. ",
+            step_num));
+    const size_t source_num = ids->at(0).lod().at(0).size() - 1;
+    PADDLE_ENFORCE_GT(
+        source_num,
+        0UL,
+        platform::errors::InvalidArgument(
+            "source_num is the sequence number of the"
+            "first decoding step, indicating by Input(Ids)[0].lod[0].size. "
+            "The number of source_num should be larger than"
+            "0, but received %d. ",
+            source_num));
+
+    for (size_t i = 0; i < step_num; ++i) {
+      PADDLE_ENFORCE_EQ(
+          ids->at(i).lod().size(),
+          2UL,
+          platform::errors::InvalidArgument(
+              "For the i step in beam search steps,"
+              "the size of Input(Ids)[i].lod() should larger than 2,"
+              "but received %d. ",
+              ids->at(i).lod().size()));
     }
-    for (Sentence<T>& sentence : sentence_vector_list[src_idx]) {
-      if (reverse) {
-        id_data.insert(id_data.end(),
-                       sentence.word_ids.rbegin(),
-                       sentence.word_ids.rend());
-        score_data.insert(
-            score_data.end(), sentence.scores.rbegin(), sentence.scores.rend());
-      } else {
-        id_data.insert(
-            id_data.end(), sentence.word_ids.begin(), sentence.word_ids.end());
-        score_data.insert(
-            score_data.end(), sentence.scores.begin(), sentence.scores.end());
-      }
 
-      sentence_level_lod.push_back(sentence_level_lod.back() +
-                                   sentence.word_ids.size());
-    }
-    source_level_lod.push_back(source_level_lod.back() +
-                               sentence_vector_list[src_idx].size());
-  }
+    size_t beam_size = context.Attr<int>("beam_size");
+    int end_id = context.Attr<int>("end_id");
 
-  auto cpu_place = std::unique_ptr<paddle::platform::CPUPlace>(
-      new paddle::platform::CPUPlace());
-  phi::CPUContext cpu_ctx(*cpu_place);
-
-  framework::LoD lod;
-  lod.push_back(source_level_lod);
-  lod.push_back(sentence_level_lod);
-
-  id_tensor->set_lod(lod);
-  id_tensor->Resize({static_cast<int64_t>(id_data.size())});
-  id_tensor->mutable_data<int64_t>(paddle::platform::CPUPlace());
-  framework::TensorFromVector<int64_t>(id_data, cpu_ctx, id_tensor);
-
-  score_tensor->set_lod(lod);
-  score_tensor->Resize({static_cast<int64_t>(score_data.size())});
-  score_tensor->mutable_data<T>(paddle::platform::CPUPlace());
-  framework::TensorFromVector<T>(score_data, cpu_ctx, score_tensor);
-}
-
-template <typename T>
-void BeamSearchDecoder<T>::Backtrace(const LoDTensorArray& step_ids,
-                                     const LoDTensorArray& step_scores,
-                                     LoDTensor* id_tensor,
-                                     LoDTensor* score_tensor) const {
-  PADDLE_ENFORCE_NE(
-      step_ids.empty(),
-      true,
-      platform::errors::InvalidArgument("Input(Ids) should not be empty."
-                                        "But the Input(Ids) is empty."));
-  PADDLE_ENFORCE_EQ(
-      step_ids.size(),
-      step_scores.size(),
-      platform::errors::InvalidArgument(
-          "The size of Input(Ids) and Input(Scores) should be "
-          "the same. But the size of Input(Ids) and Input(Scores) "
-          "are not equal."));
-  const size_t step_num = step_ids.size();
-  const size_t src_num = step_ids.at(0).lod().at(kSourceLevel).size() - 1;
-  std::vector<SentenceVector<T>> sentence_vector_list(
-      src_num, SentenceVector<T>(beam_size_));
-  std::vector<std::vector<size_t>> prefix_idx_vector_list(src_num);
-  for (int step_id = step_num - 1; step_id >= 0; --step_id) {
-    auto& cur_ids = step_ids.at(step_id);
-    auto& cur_scores = step_scores.at(step_id);
-    for (size_t src_idx = 0; src_idx < src_num; ++src_idx) {
-      // for each source sentence
-      auto& sentence_vector = sentence_vector_list.at(src_idx);
-      auto& prefix_idx_vector = prefix_idx_vector_list.at(src_idx);
-      size_t src_prefix_start = cur_ids.lod().at(kSourceLevel)[src_idx];
-      size_t src_prefix_end = cur_ids.lod().at(kSourceLevel)[src_idx + 1];
-      if (prefix_idx_vector.empty()) {  // be finished and pruned at this step
-                                        // or the last time step
-        for (size_t prefix_idx = src_prefix_start; prefix_idx < src_prefix_end;
-             ++prefix_idx) {
-          size_t candidate_start = cur_ids.lod().at(kSentenceLevel)[prefix_idx];
-          size_t candidate_end =
-              cur_ids.lod().at(kSentenceLevel)[prefix_idx + 1];
-          for (size_t candidate_idx = candidate_start;
-               candidate_idx < candidate_end;
-               ++candidate_idx) {
-            prefix_idx_vector.push_back(prefix_idx);
-            size_t idx = prefix_idx_vector.size() - 1;
-            auto cur_id = cur_ids.data<int64_t>()[candidate_idx];
-            auto cur_score = cur_scores.data<T>()[candidate_idx];
-            sentence_vector.at(idx).word_ids.push_back(cur_id);
-            sentence_vector.at(idx).scores.push_back(cur_score);
-          }
-        }
-      } else {  // use prefix_idx_vector to backtrace
-        size_t src_candidate_start =
-            cur_ids.lod().at(kSentenceLevel)[src_prefix_start];
-        size_t prefix_idx = src_prefix_start;
-        size_t candidate_num =
-            cur_ids.lod().at(kSentenceLevel)[prefix_idx + 1] -
-            cur_ids.lod().at(kSentenceLevel)[prefix_idx];
-        for (size_t idx = 0; idx < prefix_idx_vector.size(); ++idx) {
-          auto candidate_idx = prefix_idx_vector.at(idx);
-          auto cur_id = cur_ids.data<int64_t>()[candidate_idx];
-          auto cur_score = cur_scores.data<T>()[candidate_idx];
-          if (cur_id != end_id_ || sentence_vector.at(idx).word_ids.empty()) {
-            // to skip redundant end tokens
-            sentence_vector.at(idx).word_ids.push_back(cur_id);
-            sentence_vector.at(idx).scores.push_back(cur_score);
-          }
+    // prepare output
+    LoDTensor* sentenceIds = context.Output<LoDTensor>("SentenceIds");
+    LoDTensor* sentenceScores = context.Output<LoDTensor>("SentenceScores");
 
-          while (src_candidate_start + candidate_num <=
-                 candidate_idx) {  // search the corresponding prefix
-            prefix_idx++;
-            candidate_num += cur_ids.lod().at(kSentenceLevel)[prefix_idx + 1] -
-                             cur_ids.lod().at(kSentenceLevel)[prefix_idx];
-          }
-          prefix_idx_vector.at(idx) = prefix_idx;
-        }
-      }
-    }
+    BeamSearchDecodeFunctor bs(
+        *ids, *scores, sentenceIds, sentenceScores, beam_size, end_id);
+    bs.apply_mix<T>();
   }
-
-  ConvertSentenceVectorToLodTensor(
-      sentence_vector_list, id_tensor, score_tensor, true, true);
-}
+};
 
 }  // namespace operators
 }  // namespace paddle

paddle/fluid/operators/beam_search_decode_op_def.h

+/* Copyright (c) 2016 PaddlePaddle 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. */
+#pragma once
+
+#include <algorithm>
+#include <memory>
+#include <vector>
+
+#include "paddle/fluid/framework/lod_tensor.h"
+#include "paddle/fluid/framework/lod_tensor_array.h"
+#include "paddle/fluid/platform/enforce.h"
+
+namespace paddle {
+namespace operators {
+using LoDTensor = framework::LoDTensor;
+using LoDTensorArray = framework::LoDTensorArray;
+
+// all the lod have 2 levels.
+// The first is source level, the second is sentence level.
+// source level describe how many prefixes (branchs) for each source sentece
+// (beam). sentence level describe how these candidates belong to the prefixes.
+const size_t kSourceLevel = 0;
+const size_t kSentenceLevel = 1;
+
+template <typename T>
+struct Sentence {
+  std::vector<int64_t> word_ids;
+  std::vector<T> scores;
+};
+
+template <typename T>
+using SentenceVector = std::vector<Sentence<T>>;
+
+template <typename T>
+struct BeamSearchDecoder {
+  BeamSearchDecoder(size_t beam_size, int end_id)
+      : beam_size_(beam_size), end_id_(end_id) {}
+
+  /**
+   * convert the result sentence_vector for each source sentence into two
+   * LodTensor.
+   * One is all candidate sentences with word id, one is all candidate sentences
+   * with word score.
+   * Param:
+   *  sentence_vector_list: sentence_vector for each source sentence.
+   *  id_tensor: result LoDTensor for sentences of id.
+   *  score_tensor: result LoDTensor for sentences of score.
+   *  reverse: whether ids of sentence in sentence_vector_list is reversed
+   *  sort_by_score: whether to sort hypotheses of each sentence by scores.
+   */
+  void ConvertSentenceVectorToLodTensor(
+      std::vector<SentenceVector<T>> sentence_vector_list,
+      LoDTensor* id_tensor,
+      LoDTensor* score_tensor,
+      bool reverse = true,
+      bool sort_by_score = true) const;
+
+  /**
+   * Gather the hypotheses for each source sentence by backtrace though the
+   * LoDTensorArray step_ids whose lods reserve the path in the tree.
+   */
+  void Backtrace(const LoDTensorArray& step_ids,
+                 const LoDTensorArray& step_scores,
+                 LoDTensor* id_tensor,
+                 LoDTensor* score_tensor) const;
+
+  size_t beam_size_;
+  int end_id_;
+};
+
+template <typename T>
+void BeamSearchDecoder<T>::ConvertSentenceVectorToLodTensor(
+    std::vector<SentenceVector<T>> sentence_vector_list,
+    LoDTensor* id_tensor,
+    LoDTensor* score_tensor,
+    bool reverse,
+    bool sort_by_score) const {
+  size_t src_num = sentence_vector_list.size();
+
+  PADDLE_ENFORCE_NE(
+      src_num,
+      0,
+      platform::errors::InvalidArgument(
+          "src_num is the sequence number of the first decoding step"
+          ", indicating by Input(Ids)[0].lod[0].size."
+          "src_num has wrong value."
+          "src_num should not be 0,"
+          "But received %d.",
+          src_num));
+
+  std::vector<size_t> source_level_lod = {0};
+  std::vector<size_t> sentence_level_lod = {0};
+  std::vector<int64_t> id_data;
+  std::vector<T> score_data;
+
+  for (size_t src_idx = 0; src_idx < src_num; ++src_idx) {
+    if (sort_by_score) {
+      sort(sentence_vector_list[src_idx].begin(),
+           sentence_vector_list[src_idx].end(),
+           [reverse](const Sentence<T>& a, const Sentence<T>& b) {
+             if (reverse)
+               return a.scores.front() > b.scores.front();
+             else
+               return a.scores.back() > b.scores.back();
+           });
+    }
+    for (Sentence<T>& sentence : sentence_vector_list[src_idx]) {
+      if (reverse) {
+        id_data.insert(id_data.end(),
+                       sentence.word_ids.rbegin(),
+                       sentence.word_ids.rend());
+        score_data.insert(
+            score_data.end(), sentence.scores.rbegin(), sentence.scores.rend());
+      } else {
+        id_data.insert(
+            id_data.end(), sentence.word_ids.begin(), sentence.word_ids.end());
+        score_data.insert(
+            score_data.end(), sentence.scores.begin(), sentence.scores.end());
+      }
+
+      sentence_level_lod.push_back(sentence_level_lod.back() +
+                                   sentence.word_ids.size());
+    }
+    source_level_lod.push_back(source_level_lod.back() +
+                               sentence_vector_list[src_idx].size());
+  }
+
+  auto cpu_place = std::unique_ptr<paddle::platform::CPUPlace>(
+      new paddle::platform::CPUPlace());
+  phi::CPUContext cpu_ctx(*cpu_place);
+
+  framework::LoD lod;
+  lod.push_back(source_level_lod);
+  lod.push_back(sentence_level_lod);
+
+  id_tensor->set_lod(lod);
+  id_tensor->Resize({static_cast<int64_t>(id_data.size())});
+  id_tensor->mutable_data<int64_t>(paddle::platform::CPUPlace());
+  framework::TensorFromVector<int64_t>(id_data, cpu_ctx, id_tensor);
+
+  score_tensor->set_lod(lod);
+  score_tensor->Resize({static_cast<int64_t>(score_data.size())});
+  score_tensor->mutable_data<T>(paddle::platform::CPUPlace());
+  framework::TensorFromVector<T>(score_data, cpu_ctx, score_tensor);
+}
+
+template <typename T>
+void BeamSearchDecoder<T>::Backtrace(const LoDTensorArray& step_ids,
+                                     const LoDTensorArray& step_scores,
+                                     LoDTensor* id_tensor,
+                                     LoDTensor* score_tensor) const {
+  PADDLE_ENFORCE_NE(
+      step_ids.empty(),
+      true,
+      platform::errors::InvalidArgument("Input(Ids) should not be empty."
+                                        "But the Input(Ids) is empty."));
+  PADDLE_ENFORCE_EQ(
+      step_ids.size(),
+      step_scores.size(),
+      platform::errors::InvalidArgument(
+          "The size of Input(Ids) and Input(Scores) should be "
+          "the same. But the size of Input(Ids) and Input(Scores) "
+          "are not equal."));
+  const size_t step_num = step_ids.size();
+  const size_t src_num = step_ids.at(0).lod().at(kSourceLevel).size() - 1;
+  std::vector<SentenceVector<T>> sentence_vector_list(
+      src_num, SentenceVector<T>(beam_size_));
+  std::vector<std::vector<size_t>> prefix_idx_vector_list(src_num);
+  for (int step_id = step_num - 1; step_id >= 0; --step_id) {
+    auto& cur_ids = step_ids.at(step_id);
+    auto& cur_scores = step_scores.at(step_id);
+    for (size_t src_idx = 0; src_idx < src_num; ++src_idx) {
+      // for each source sentence
+      auto& sentence_vector = sentence_vector_list.at(src_idx);
+      auto& prefix_idx_vector = prefix_idx_vector_list.at(src_idx);
+      size_t src_prefix_start = cur_ids.lod().at(kSourceLevel)[src_idx];
+      size_t src_prefix_end = cur_ids.lod().at(kSourceLevel)[src_idx + 1];
+      if (prefix_idx_vector.empty()) {  // be finished and pruned at this step
+                                        // or the last time step
+        for (size_t prefix_idx = src_prefix_start; prefix_idx < src_prefix_end;
+             ++prefix_idx) {
+          size_t candidate_start = cur_ids.lod().at(kSentenceLevel)[prefix_idx];
+          size_t candidate_end =
+              cur_ids.lod().at(kSentenceLevel)[prefix_idx + 1];
+          for (size_t candidate_idx = candidate_start;
+               candidate_idx < candidate_end;
+               ++candidate_idx) {
+            prefix_idx_vector.push_back(prefix_idx);
+            size_t idx = prefix_idx_vector.size() - 1;
+            auto cur_id = cur_ids.data<int64_t>()[candidate_idx];
+            auto cur_score = cur_scores.data<T>()[candidate_idx];
+            sentence_vector.at(idx).word_ids.push_back(cur_id);
+            sentence_vector.at(idx).scores.push_back(cur_score);
+          }
+        }
+      } else {  // use prefix_idx_vector to backtrace
+        size_t src_candidate_start =
+            cur_ids.lod().at(kSentenceLevel)[src_prefix_start];
+        size_t prefix_idx = src_prefix_start;
+        size_t candidate_num =
+            cur_ids.lod().at(kSentenceLevel)[prefix_idx + 1] -
+            cur_ids.lod().at(kSentenceLevel)[prefix_idx];
+        for (size_t idx = 0; idx < prefix_idx_vector.size(); ++idx) {
+          auto candidate_idx = prefix_idx_vector.at(idx);
+          auto cur_id = cur_ids.data<int64_t>()[candidate_idx];
+          auto cur_score = cur_scores.data<T>()[candidate_idx];
+          if (cur_id != end_id_ || sentence_vector.at(idx).word_ids.empty()) {
+            // to skip redundant end tokens
+            sentence_vector.at(idx).word_ids.push_back(cur_id);
+            sentence_vector.at(idx).scores.push_back(cur_score);
+          }
+
+          while (src_candidate_start + candidate_num <=
+                 candidate_idx) {  // search the corresponding prefix
+            prefix_idx++;
+            candidate_num += cur_ids.lod().at(kSentenceLevel)[prefix_idx + 1] -
+                             cur_ids.lod().at(kSentenceLevel)[prefix_idx];
+          }
+          prefix_idx_vector.at(idx) = prefix_idx;
+        }
+      }
+    }
+  }
+
+  ConvertSentenceVectorToLodTensor(
+      sentence_vector_list, id_tensor, score_tensor, true, true);
+}
+
+}  // namespace operators
+};  // namespace paddle

paddle/fluid/operators/beam_search_decode_op_xpu.cc

+/* Copyright (c) 2016 PaddlePaddle 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. */
+
+#ifdef PADDLE_WITH_XPU
+
+#include "paddle/fluid/operators/beam_search_decode_op_xpu.h"
+#include "paddle/fluid/framework/op_registry.h"
+
+namespace paddle {
+namespace operators {
+
+template <typename DeviceContext, typename T>
+class BeamSearchDecodeXPUKernel : public framework::OpKernel<T> {
+ public:
+  void Compute(const framework::ExecutionContext& context) const override {
+    const LoDTensorArray* ids = context.Input<LoDTensorArray>("Ids");
+    const LoDTensorArray* scores = context.Input<LoDTensorArray>("Scores");
+    const size_t step_num = ids->size();
+    PADDLE_ENFORCE_GT(
+        step_num,
+        0UL,
+        platform::errors::InvalidArgument(
+            "beam search steps, which is the"
+            "size of Input(Ids) LoDTensorArray. beam search steps should "
+            "be larger than 0, but received %d. ",
+            step_num));
+
+    const size_t source_num = ids->at(0).lod().at(0).size() - 1;
+    PADDLE_ENFORCE_GT(
+        source_num,
+        0UL,
+        platform::errors::InvalidArgument(
+            "source_num is the sequence number of the"
+            "first decoding step, indicating by Input(Ids)[0].lod[0].size. "
+            "The number of source_num should be larger than"
+            "0, but received %d. ",
+            source_num));
+
+    for (size_t i = 0; i < step_num; ++i) {
+      PADDLE_ENFORCE_EQ(
+          ids->at(i).lod().size(),
+          2UL,
+          platform::errors::InvalidArgument(
+              "For the i step in beam search steps,"
+              "the size of Input(Ids)[i].lod() should larger than 2,"
+              "but received %d. ",
+              ids->at(i).lod().size()));
+    }
+
+    size_t beam_size = context.Attr<int>("beam_size");
+    int end_id = context.Attr<int>("end_id");
+
+    // prepare output
+    LoDTensor* sentenceIds = nullptr;
+    LoDTensor* sentenceScores = nullptr;
+
+    LoDTensor* sentenceIds_temp = context.Output<LoDTensor>("SentenceIds");
+    LoDTensor* sentenceScores_temp =
+        context.Output<LoDTensor>("SentenceScores");
+
+    if (platform::is_xpu_place(ids->at(0).place())) {
+      sentenceIds = new LoDTensor();
+      sentenceIds->set_lod(sentenceIds_temp->lod());
+    }
+
+    if (platform::is_xpu_place(ids->at(0).place())) {
+      sentenceScores = new LoDTensor();
+      sentenceScores->set_lod(sentenceScores_temp->lod());
+    }
+
+    BeamSearchDecodeXPUFunctor bs_xpu(
+        *ids, *scores, sentenceIds, sentenceScores, beam_size, end_id);
+    bs_xpu.apply_xpu<T>();
+
+    if (platform::is_xpu_place(ids->at(0).place())) {
+      int r = 0;
+      r = CopyTensorByXPU<int64_t>(
+          *sentenceIds, sentenceIds_temp, 1, ids->at(0).place());
+      PADDLE_ENFORCE_EQ(
+          r,
+          xpu::Error_t::SUCCESS,
+          platform::errors::External(
+              "Execute function CopyTensorByXPU failed by [%d]", r));
+
+      r = CopyTensorByType(
+          *sentenceScores, sentenceScores_temp, 1, ids->at(0).place());
+      PADDLE_ENFORCE_EQ(
+          r,
+          xpu::Error_t::SUCCESS,
+          platform::errors::External(
+              "Execute function CopyTensorByXPU failed by [%d]", r));
+    }
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle
+
+namespace ops = paddle::operators;
+REGISTER_OP_XPU_KERNEL(
+    beam_search_decode,
+    ops::BeamSearchDecodeXPUKernel<paddle::platform::XPUDeviceContext, float>,
+    ops::BeamSearchDecodeXPUKernel<paddle::platform::XPUDeviceContext, double>,
+    ops::BeamSearchDecodeXPUKernel<paddle::platform::XPUDeviceContext,
+                                   paddle::platform::float16>,
+    ops::BeamSearchDecodeXPUKernel<paddle::platform::XPUDeviceContext, int>,
+    ops::BeamSearchDecodeXPUKernel<paddle::platform::XPUDeviceContext,
+                                   int64_t>);
+#endif

paddle/fluid/operators/beam_search_decode_op_xpu.h

+/* Copyright (c) 2016 PaddlePaddle 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. */
+#pragma once
+
+#include "paddle/fluid/operators/beam_search_decode_op_def.h"
+
+namespace paddle {
+namespace operators {
+
+int SetMeta(const LoDTensor& srcTensor, LoDTensor* dstTensor) {
+  if (srcTensor.dtype() == paddle::experimental::DataType::INT32 ||
+      srcTensor.dtype() == paddle::experimental::DataType::INT64 ||
+      srcTensor.dtype() == paddle::experimental::DataType::FLOAT32 ||
+      srcTensor.dtype() == paddle::experimental::DataType::FLOAT16 ||
+      srcTensor.dtype() == paddle::experimental::DataType::FLOAT64) {
+    const phi::DenseTensorMeta meta_data(srcTensor.dtype(), srcTensor.dims());
+    dstTensor->set_meta(meta_data);
+  } else {
+    return xpu::Error_t::INVALID_PARAM;
+  }
+
+  return xpu::Error_t::SUCCESS;
+}
+template <typename T>
+int CopyTensorByXPU(const LoDTensor& srcTensor,
+                    LoDTensor* dstTensor,
+                    int flag,
+                    const Place& place) {
+  const T* srcData = srcTensor.template data<T>();
+  if (nullptr == srcData || nullptr == dstTensor || flag < 0 || flag > 1)
+    return xpu::Error_t::INVALID_PARAM;
+
+  int r = SetMeta(srcTensor, dstTensor);
+  PADDLE_ENFORCE_EQ(
+      r,
+      xpu::Error_t::SUCCESS,
+      platform::errors::External("Execute function SetMeta failed by [%d]", r));
+
+  if (flag == 0) {
+    T* dstData =
+        dstTensor->template mutable_data<T>(paddle::platform::CPUPlace());
+    paddle::memory::Copy(paddle::platform::CPUPlace(),
+                         dstData,
+                         place,
+                         srcData,
+                         srcTensor.numel() * sizeof(T));
+  } else {
+    T* dstData = dstTensor->template mutable_data<T>(place);
+    paddle::memory::Copy(place,
+                         dstData,
+                         paddle::platform::CPUPlace(),
+                         srcData,
+                         srcTensor.numel() * sizeof(T));
+  }
+
+  return xpu::Error_t::SUCCESS;
+}
+
+const int CopyTensorByType(const LoDTensor& srcTensor,
+                           LoDTensor* dstTensor,
+                           int flag,
+                           const Place& place) {
+  int r = 0;
+  if (srcTensor.dtype() == paddle::experimental::DataType::FLOAT32)
+    r = CopyTensorByXPU<float>(srcTensor, dstTensor, flag, place);
+  else if (srcTensor.dtype() == paddle::experimental::DataType::FLOAT16)
+    r = CopyTensorByXPU<paddle::platform::float16>(
+        srcTensor, dstTensor, flag, place);
+  else if (srcTensor.dtype() == paddle::experimental::DataType::FLOAT64)
+    r = CopyTensorByXPU<double>(srcTensor, dstTensor, flag, place);
+  else if (srcTensor.dtype() == paddle::experimental::DataType::INT32)
+    r = CopyTensorByXPU<int>(srcTensor, dstTensor, flag, place);
+  else if (srcTensor.dtype() == paddle::experimental::DataType::INT64)
+    r = CopyTensorByXPU<int64_t>(srcTensor, dstTensor, flag, place);
+  else
+    return xpu::Error_t::INVALID_PARAM;
+
+  PADDLE_ENFORCE_EQ(r,
+                    xpu::Error_t::SUCCESS,
+                    platform::errors::External(
+                        "Execute function CopyTensorByXPU failed by [%d]", r));
+
+  return xpu::Error_t::SUCCESS;
+}
+
+struct BeamSearchDecodeXPUFunctor {
+  BeamSearchDecodeXPUFunctor(const LoDTensorArray& step_ids,
+                             const LoDTensorArray& step_scores,
+                             LoDTensor* id_tensor,
+                             LoDTensor* score_tensor,
+                             size_t beam_size,
+                             int end_id)
+      : beam_size_(beam_size),
+        end_id_(end_id),
+        id_tensor_(id_tensor),
+        score_tensor_(score_tensor) {
+    int r = 0;
+
+    // First make a copy of XPU data on CPU
+    if (platform::is_xpu_place(step_ids[0].place())) {
+      // Copy all tensors in the input tensor array
+      for (auto& step_id : step_ids) {
+        framework::LoDTensor out;
+        if (step_id.numel() > 0) {
+          r = CopyTensorByType(step_id, &out, 0, step_ids[0].place());
+          PADDLE_ENFORCE_EQ(
+              r,
+              xpu::Error_t::SUCCESS,
+              platform::errors::External(
+                  "Execute function CopyTensorByXPU failed by [%d]", r));
+        }
+
+        out.set_lod(step_id.lod());
+        step_ids_.push_back(out);
+      }
+    }
+
+    if (platform::is_xpu_place(step_scores[0].place())) {
+      // Copy all tensors in the input tensor array
+      for (auto& step_score : step_scores) {
+        framework::LoDTensor out;
+        if (step_score.numel() > 0) {
+          r = CopyTensorByType(step_score, &out, 0, step_scores[0].place());
+          PADDLE_ENFORCE_EQ(
+              r,
+              xpu::Error_t::SUCCESS,
+              platform::errors::External(
+                  "Execute function CopyTensorByType failed by [%d]", r));
+        }
+
+        out.set_lod(step_score.lod());
+        step_scores_.push_back(out);
+      }
+    }
+  }
+
+  template <typename T>
+  void apply_xpu() const {
+    if (std::is_same<bool, T>::value) {
+      PADDLE_THROW(platform::errors::InvalidArgument(
+          "beam search decode op does not support bool!"));
+    } else {
+      BeamSearchDecoder<T> beam_search_decoder(beam_size_, end_id_);
+      beam_search_decoder.Backtrace(
+          step_ids_, step_scores_, id_tensor_, score_tensor_);
+    }
+  }
+
+  size_t beam_size_;
+  int end_id_;
+  // TODO(Superjomn) Here might result serious performance issue in the
+  // concurrency
+  // scenarios.
+  LoDTensorArray step_ids_ = LoDTensorArray();
+  LoDTensorArray step_scores_ = LoDTensorArray();
+  LoDTensor* id_tensor_;
+  LoDTensor* score_tensor_;
+};
+
+}  // namespace operators
+};  // namespace paddle

paddle/fluid/operators/beam_search_decode_op_xpu_test.cc

+/* Copyright (c) 2016 PaddlePaddle 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 "paddle/fluid/operators/beam_search_decode_op_xpu.h"
+
+#include "gtest/gtest.h"
+
+using CPUPlace = paddle::platform::CPUPlace;
+using XPUPlace = paddle::platform::XPUPlace;
+using LoD = paddle::framework::LoD;
+using LoDTensor = paddle::framework::LoDTensor;
+using LoDTensorArray = paddle::framework::LoDTensorArray;
+
+template <typename T>
+using BeamSearchDecoder = paddle::operators::BeamSearchDecoder<T>;
+template <typename T>
+using Sentence = paddle::operators::Sentence<T>;
+template <typename T>
+using SentenceVector = paddle::operators::SentenceVector<T>;
+
+namespace paddle {
+namespace test {
+
+void GenerateXPUExample(const std::vector<size_t>& level_0,
+                        const std::vector<size_t>& level_1,
+                        const std::vector<int>& data,
+                        LoDTensorArray* ids,
+                        LoDTensorArray* scores) {
+  PADDLE_ENFORCE_EQ(level_0.back(),
+                    level_1.size() - 1,
+                    platform::errors::InvalidArgument(
+                        "source level is used to describe candidate set"
+                        ", so it's element should less than levle_1 length. "
+                        "And the value of source"
+                        "level is %d. ",
+                        level_1.size() - 1));
+  PADDLE_ENFORCE_EQ(level_1.back(),
+                    data.size(),
+                    platform::errors::InvalidArgument(
+                        "the lowest level is used to describe data"
+                        ", so it's last element should be data length %d. ",
+                        data.size()));
+
+  CPUPlace place;
+  int XPU_PlaceNo = 0;
+  if (std::getenv("FLAGS_selected_xpus") != nullptr)
+    XPU_PlaceNo = atoi(std::getenv("FLAGS_selected_xpus"));
+  else if (std::getenv("XPU_VISIBLE_DEVICES") != nullptr)
+    XPU_PlaceNo = atoi(std::getenv("XPU_VISIBLE_DEVICES"));
+
+  XPUPlace xpu_place(XPU_PlaceNo);
+
+  LoD lod;
+  lod.push_back(level_0);
+  lod.push_back(level_1);
+
+  // Ids
+  LoDTensor tensor_id_cpu;
+  tensor_id_cpu.set_lod(lod);
+  tensor_id_cpu.Resize({static_cast<int64_t>(data.size())});
+  // malloc memory
+  int64_t* id_cpu_ptr = tensor_id_cpu.mutable_data<int64_t>(place);
+  for (size_t i = 0; i < data.size(); ++i) {
+    id_cpu_ptr[i] = static_cast<int64_t>(data.at(i));
+  }
+
+  LoDTensor tensor_id;
+  const phi::DenseTensorMeta meta_data_id(paddle::experimental::DataType::INT64,
+                                          tensor_id_cpu.dims());
+  tensor_id.set_meta(meta_data_id);
+  tensor_id.set_lod(lod);
+
+  int64_t* id_ptr = tensor_id.mutable_data<int64_t>(xpu_place);
+  paddle::memory::Copy(paddle::platform::XPUPlace(XPU_PlaceNo),
+                       id_ptr,
+                       paddle::platform::CPUPlace(),
+                       id_cpu_ptr,
+                       tensor_id_cpu.numel() * sizeof(int64_t));
+
+  // Scores
+  LoDTensor tensor_score_cpu;
+  tensor_score_cpu.set_lod(lod);
+  tensor_score_cpu.Resize({static_cast<int64_t>(data.size())});
+  // malloc memory
+  float* score_cpu_ptr = tensor_score_cpu.mutable_data<float>(place);
+  for (size_t i = 0; i < data.size(); ++i) {
+    score_cpu_ptr[i] = static_cast<float>(data.at(i));
+  }
+
+  LoDTensor tensor_score;
+  const phi::DenseTensorMeta meta_data_score(
+      paddle::experimental::DataType::FLOAT32, tensor_score_cpu.dims());
+  tensor_score.set_meta(meta_data_score);
+  tensor_score.set_lod(lod);
+
+  float* score_ptr = tensor_score.mutable_data<float>(xpu_place);
+  paddle::memory::Copy(paddle::platform::XPUPlace(XPU_PlaceNo),
+                       score_ptr,
+                       paddle::platform::CPUPlace(),
+                       score_cpu_ptr,
+                       tensor_score_cpu.numel() * sizeof(float));
+
+  ids->push_back(tensor_id);
+  scores->push_back(tensor_score);
+}
+
+}  // namespace test
+}  // namespace paddle
+
+TEST(BeamSearchDecodeOpXPU, Backtrace) {
+  CPUPlace place;
+
+  // Construct sample data with 5 steps and 2 source sentences
+  // beam_size = 2, start_id = 0, end_id = 1
+  LoDTensorArray ids;
+  LoDTensorArray scores;
+
+  paddle::test::GenerateXPUExample(std::vector<size_t>{0, 1, 2},
+                                   std::vector<size_t>{0, 1, 2},
+                                   std::vector<int>{0, 0},
+                                   &ids,
+                                   &scores);  // start with start_id
+  paddle::test::GenerateXPUExample(std::vector<size_t>{0, 1, 2},
+                                   std::vector<size_t>{0, 2, 4},
+                                   std::vector<int>{2, 3, 4, 5},
+                                   &ids,
+                                   &scores);
+  paddle::test::GenerateXPUExample(std::vector<size_t>{0, 2, 4},
+                                   std::vector<size_t>{0, 2, 2, 4, 4},
+                                   std::vector<int>{3, 1, 5, 4},
+                                   &ids,
+                                   &scores);
+  paddle::test::GenerateXPUExample(std::vector<size_t>{0, 2, 4},
+                                   std::vector<size_t>{0, 1, 2, 3, 4},
+                                   std::vector<int>{1, 1, 3, 5},
+                                   &ids,
+                                   &scores);
+  paddle::test::GenerateXPUExample(
+      std::vector<size_t>{0, 2, 4},
+      std::vector<size_t>{0, 0, 0, 2, 2},  // the branchs of the first source
+                                           // sentence are pruned since finished
+      std::vector<int>{5, 1},
+      &ids,
+      &scores);
+
+  ASSERT_EQ(ids.size(), 5UL);
+  ASSERT_EQ(scores.size(), 5UL);
+
+  LoDTensor id_tensor_cpu;
+  LoDTensor score_tensor_cpu;
+
+  paddle::operators::BeamSearchDecodeXPUFunctor bs_xpu(
+      ids, scores, &id_tensor_cpu, &score_tensor_cpu, 2, 1);
+  bs_xpu.apply_xpu<float>();
+
+  LoD lod = id_tensor_cpu.lod();
+  std::vector<size_t> expect_source_lod = {0, 2, 4};
+  ASSERT_EQ(lod[0], expect_source_lod);
+
+  std::vector<size_t> expect_sentence_lod = {0, 4, 7, 12, 17};
+  ASSERT_EQ(lod[1], expect_sentence_lod);
+
+  std::vector<int> expect_data = {
+      0, 2, 3, 1, 0, 2, 1, 0, 4, 5, 3, 5, 0, 4, 5, 3, 1};
+  ASSERT_EQ(id_tensor_cpu.dims()[0], static_cast<int64_t>(expect_data.size()));
+
+  for (size_t i = 0; i < expect_data.size(); ++i) {
+    ASSERT_EQ(id_tensor_cpu.data<int64_t>()[i],
+              static_cast<int64_t>(expect_data[i]));
+  }
+
+  for (int64_t i = 0; i < id_tensor_cpu.dims()[0]; ++i) {
+    ASSERT_EQ(score_tensor_cpu.data<float>()[i],
+              static_cast<float>(id_tensor_cpu.data<int64_t>()[i]));
+  }
+}

paddle/fluid/operators/beam_search_op_xpu.cc

@@ -12,6 +12,8 @@ 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 PADDLE_WITH_XPU
+
 #include "paddle/fluid/framework/op_registry.h"
 #include "paddle/fluid/operators/beam_search_op.h"
 
@@ -22,3 +24,4 @@ REGISTER_OP_XPU_KERNEL(
     ops::BeamSearchOpKernel<paddle::platform::XPUDeviceContext, double>,
     ops::BeamSearchOpKernel<paddle::platform::XPUDeviceContext, int>,
     ops::BeamSearchOpKernel<paddle::platform::XPUDeviceContext, int64_t>);
+#endif

paddle/fluid/operators/math/beam_search_xpu.cc

@@ -12,6 +12,7 @@ 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 "paddle/fluid/memory/memcpy.h"
 #include "paddle/fluid/operators/math/beam_search.h"
 
 namespace phi {
@@ -28,6 +29,28 @@ class XPUDeviceContext;
 namespace paddle {
 namespace operators {
 namespace math {
+template <typename T>
+int CopyData(const T *x, T **y, int len, const Place &place) {
+  if (nullptr == x || nullptr == y || len <= 0)
+    return xpu::Error_t::INVALID_PARAM;
+
+  *y = reinterpret_cast<T *>(malloc(sizeof(T) * len));
+
+  paddle::memory::Copy(
+      paddle::platform::CPUPlace(), *y, place, x, len * sizeof(T));
+  return xpu::Error_t::SUCCESS;
+}
+
+template <typename T>
+void CopyDataByCondition(const T *x, T **y, int len, const Place &place) {
+  if (x != nullptr) {
+    int r = CopyData(x, y, len, place);
+    PADDLE_ENFORCE_EQ(
+        r,
+        xpu::Error_t::SUCCESS,
+        platform::errors::External("Copy data form xpu to cpu failed"));
+  }
+}
 
 template <typename T>
 class BeamSearchFunctor<platform::XPUDeviceContext, T> {
@@ -54,7 +77,8 @@ class BeamSearchFunctor<platform::XPUDeviceContext, T> {
                                         level,
                                         beam_size,
                                         end_id,
-                                        is_accumulated);
+                                        is_accumulated,
+                                        ids->place());
     auto selected_items = ToMap(items, high_level.back());
     if (FLAGS_v == 3) {
       VLOG(3) << "selected_items:";
@@ -66,7 +90,8 @@ class BeamSearchFunctor<platform::XPUDeviceContext, T> {
       }
     }
 
-    PruneEndBeams(pre_ids, abs_lod, &selected_items, level, end_id);
+    PruneEndBeams(
+        pre_ids, abs_lod, &selected_items, level, end_id, ids->place());
     // calculate the output tensor's height
     size_t num_instances = std::accumulate(
         std::begin(selected_items),
@@ -164,8 +189,13 @@ class BeamSearchFunctor<platform::XPUDeviceContext, T> {
                      const framework::LoD &abs_lod,
                      std::vector<std::vector<Item>> *items,
                      size_t lod_level,
-                     int end_id) {
-    auto *pre_ids_data = pre_ids->data<int64_t>();
+                     int end_id,
+                     const Place &place) {
+    auto *pre_ids_data_xpu = pre_ids->data<int64_t>();
+    int64_t *pre_ids_data = nullptr;
+    CopyDataByCondition<int64_t>(
+        pre_ids_data_xpu, &pre_ids_data, pre_ids->numel(), place);
+
     auto &high_level = abs_lod[lod_level];
     for (size_t src_idx = 0; src_idx < high_level.size() - 1; ++src_idx) {
       size_t src_prefix_start = high_level[src_idx];
@@ -189,6 +219,7 @@ class BeamSearchFunctor<platform::XPUDeviceContext, T> {
           items->at(offset).clear();
       }
     }
+    free(pre_ids_data);
   }
 
   /*
@@ -213,6 +244,7 @@ class BeamSearchFunctor<platform::XPUDeviceContext, T> {
     std::vector<Item> &top_beam = *top_beam_ptr;
 
     size_t num_beams = top_beam.size();
+
     if (num_beams < beam_size) {
       top_beam.resize(num_beams + 1);
       num_beams++;
@@ -244,17 +276,31 @@ class BeamSearchFunctor<platform::XPUDeviceContext, T> {
       size_t lod_level,
       size_t beam_size,
       int end_id,
-      bool is_accumulated) {
+      bool is_accumulated,
+      const Place &place) {
     std::vector<std::vector<Item>> result;
 
     // find the current candidates
     auto abs_lod = framework::ToAbsOffset(scores->lod());
 
-    auto *pre_ids_data = pre_ids->data<int64_t>();
-    auto *pre_scores_data = pre_scores->data<float>();
+    auto *pre_ids_data_xpu = pre_ids->data<int64_t>();
+    int64_t *pre_ids_data = nullptr;
+    CopyDataByCondition<int64_t>(
+        pre_ids_data_xpu, &pre_ids_data, pre_ids->numel(), place);
+
+    auto *pre_scores_data_xpu = pre_scores->data<float>();
+    float *pre_scores_data = nullptr;
+    CopyDataByCondition<float>(
+        pre_scores_data_xpu, &pre_scores_data, pre_scores->numel(), place);
+
+    auto *ids_data_xpu = ids ? ids->data<int64_t>() : nullptr;
+    int64_t *ids_data = nullptr;
+    CopyDataByCondition<int64_t>(ids_data_xpu, &ids_data, ids->numel(), place);
 
-    auto *ids_data = ids ? ids->data<int64_t>() : nullptr;
-    auto *scores_data = scores->data<float>();
+    auto *scores_data_xpu = scores->data<float>();
+    float *scores_data = nullptr;
+    CopyDataByCondition<float>(
+        scores_data_xpu, &scores_data, scores->numel(), place);
 
     size_t num_seqs = scores->NumElements(lod_level);
     size_t seq_width = 1;
@@ -273,6 +319,7 @@ class BeamSearchFunctor<platform::XPUDeviceContext, T> {
            ++offset) {
         auto pre_id = pre_ids_data[offset];
         auto pre_score = pre_scores_data[offset];
+
         if (pre_id == end_id) {
           // Allocate all probability mass to end_id for finished branchs and
           // the other candidate ids can be ignored.
@@ -285,6 +332,7 @@ class BeamSearchFunctor<platform::XPUDeviceContext, T> {
             float score = is_accumulated
                               ? scores_data[index]
                               : pre_score + std::log(scores_data[index]);
+
             Item item(offset, id, score);
             Insert(&top_beam, item, beam_size);
           }
@@ -304,6 +352,11 @@ class BeamSearchFunctor<platform::XPUDeviceContext, T> {
       }
     }
 
+    free(pre_ids_data);
+    free(pre_scores_data);
+    free(ids_data);
+    free(scores_data);
+
     return result;
   }
 };

paddle/fluid/platform/device/xpu/xpu2_op_list.h

@@ -61,6 +61,12 @@ XPUOpMap& get_kl2_ops() {
                      pOpKernelType(vartype::FP64, XPUPlace()),
                      pOpKernelType(vartype::INT32, XPUPlace()),
                      pOpKernelType(vartype::INT64, XPUPlace())})},
+      {"beam_search_decode",
+       XPUKernelSet({pOpKernelType(vartype::FP32, XPUPlace()),
+                     pOpKernelType(vartype::FP64, XPUPlace()),
+                     pOpKernelType(vartype::FP16, XPUPlace()),
+                     pOpKernelType(vartype::INT32, XPUPlace()),
+                     pOpKernelType(vartype::INT64, XPUPlace())})},
       {"bilinear_interp_v2",
        XPUKernelSet({pOpKernelType(vartype::FP32, XPUPlace())})},
       {"bilinear_interp_v2_grad",