chore: import upstream snapshot with attribution

paddle/phi/kernels/cpu/shuffle_batch_kernel.cc

@@ -0,0 +1,118 @@
+// Copyright (c) 2022 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/phi/kernels/shuffle_batch_kernel.h"
+#include "paddle/phi/core/kernel_registry.h"
+#include "paddle/phi/core/tensor_utils.h"
+
+namespace phi {
+
+template <typename T, typename Context>
+void ShuffleBatchKernel(const Context& dev_ctx,
+                        const DenseTensor& x,
+                        const DenseTensor& seed,
+                        int startup_seed,
+                        DenseTensor* out,
+                        DenseTensor* shuffleidx,
+                        DenseTensor* seed_out) {
+  auto x_embed_size = x.dims()[x.dims().size() - 1];
+  int elem_size = 1;
+  for (auto i = 0; i < x.dims().size() - 1; i++)
+    elem_size *= static_cast<int>(x.dims()[i]);
+
+  std::vector<int64_t> idx_vec;  // record shuffled order
+  idx_vec.reserve(elem_size);
+  for (int i = 0; i < elem_size; i++) {
+    idx_vec.push_back(i);
+  }
+  int64_t seed_int = 0;
+  if (seed.initialized()) {
+    seed_int = *seed.data<int64_t>();
+  } else {
+    seed_int = startup_seed;
+  }
+  std::default_random_engine engine;
+  engine.seed(seed_int);
+
+  auto custom_random_shuffle = [&idx_vec]() {
+    std::random_device rnd;
+    int64_t seed_tmp = rnd();
+    std::default_random_engine rng(seed_tmp);
+    const int n = static_cast<int>(idx_vec.size());
+    std::vector<int> v(n);
+    std::iota(v.begin(), v.end(), 0);
+    std::vector<bool> visit(n, false);
+    while (!v.empty()) {
+      std::shuffle(v.begin(), v.end(), rng);
+      int tmp = v.back();
+      v.pop_back();
+      if (v.empty()) {
+        std::uniform_int_distribution<int> distr(0, n - 2);
+        idx_vec[tmp] = tmp;
+        std::swap(idx_vec[tmp], idx_vec[(distr(rng) + tmp + 1) % n]);
+        return;
+      }
+      visit[tmp] = true;
+      std::shuffle(v.begin(), v.end(), rng);
+      int curr = v.back();
+      v.pop_back();
+      v.push_back(tmp);
+      idx_vec[tmp] = curr;
+      while (!visit[curr]) {
+        visit[curr] = true;
+        std::shuffle(v.begin(), v.end(), rng);
+        idx_vec[curr] = v.back();
+        v.pop_back();
+        curr = static_cast<int>(idx_vec[curr]);
+      }
+    }
+  };
+  custom_random_shuffle();
+  // change shuffle to custom_random_shuffle
+  // std::shuffle(idx_vec.begin(), idx_vec.end(), engine);
+
+  // ShuffleIdx record shuffle order
+  shuffleidx->Resize({(int64_t)idx_vec.size()});
+  auto* shuffleidx_data = dev_ctx.template HostAlloc<int64_t>(shuffleidx);
+
+  for (size_t i = 0; i < idx_vec.size(); i++) {
+    shuffleidx_data[i] = idx_vec[i];
+  }
+  // copy data according to idx_vec
+  auto* x_data = x.data<T>();
+  auto* out_data = dev_ctx.template HostAlloc<T>(out);
+
+  for (auto i = 0; i < elem_size; i++) {
+    memcpy(out_data + idx_vec[i] * x_embed_size,
+           x_data + i * x_embed_size,
+           x_embed_size * sizeof(T));
+  }
+  // set new seed
+  seed_out->Resize({1});
+  auto* seed_out_data = dev_ctx.template HostAlloc<int64_t>(seed_out);
+  *seed_out_data = engine();
+}
+}  // namespace phi
+
+PD_REGISTER_KERNEL(shuffle_batch,
+                   CPU,
+                   ALL_LAYOUT,
+                   phi::ShuffleBatchKernel,
+                   float,
+                   double,
+                   int32_t,
+                   int64_t) {
+  kernel->OutputAt(1).SetDataType(phi::DataType::INT64);
+  kernel->OutputAt(2).SetDataType(phi::DataType::INT64);
+}