chore: import upstream snapshot with attribution

paddle/phi/kernels/gpu/c_concat_kernel.cu

@@ -0,0 +1,124 @@
+// Copyright (c) 2024 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 <vector>
+
+#include "paddle/phi/api/include/tensor.h"
+#include "paddle/phi/backends/context_pool.h"
+#include "paddle/phi/core/kernel_registry.h"
+#include "paddle/phi/kernels/c_concat_kernel.h"
+#include "paddle/phi/kernels/funcs/concat_and_split_functor.h"
+
+#if defined(PADDLE_WITH_NCCL) || defined(PADDLE_WITH_RCCL)
+#include "paddle/phi/core/distributed/nccl_comm_context.h"
+#endif
+#if defined(PADDLE_WITH_FLAGCX)
+#include "paddle/phi/core/distributed/flagcx_comm_context.h"
+#endif
+
+namespace phi {
+
+template <typename T, typename Context>
+void CConcatKernel(const Context& dev_ctx,
+                   const DenseTensor& x_in,
+                   int rank,
+                   int nranks,
+                   int ring_id UNUSED,
+                   bool use_calc_stream UNUSED,
+                   bool use_model_parallel UNUSED,
+                   DenseTensor* out) {
+#if defined(PADDLE_WITH_NCCL) || defined(PADDLE_WITH_RCCL)
+  auto x = &x_in;
+  PADDLE_ENFORCE_GE(rank,
+                    0,
+                    common::errors::PreconditionNotMet(
+                        "The value of rank (%d) for c_concat must be "
+                        "greater than or equal to 0.",
+                        rank));
+  PADDLE_ENFORCE_GE(nranks,
+                    2,
+                    common::errors::PreconditionNotMet(
+                        "The value of nranks (%d) for c_concat must be "
+                        "greater than or equal to 2.",
+                        nranks));
+  PADDLE_ENFORCE_LT(rank,
+                    nranks,
+                    common::errors::PreconditionNotMet(
+                        "The value of rank (%d) for c_concat must be "
+                        "less than that of nranks (%d).",
+                        rank,
+                        nranks));
+
+  DenseTensor temp_out;
+  DDim temp_out_dims = x->dims();
+  temp_out_dims[0] *= nranks;
+  temp_out.Resize(temp_out_dims);
+  dev_ctx.template Alloc<T>(&temp_out);
+
+  gpuStream_t stream = nullptr;
+
+#if defined(PADDLE_WITH_FLAGCX) && defined(PADDLE_KERNEL_WITH_FLAGCX)
+  distributed::FlagcxCommContext* comm_ctx = nullptr;
+  comm_ctx =
+      static_cast<distributed::FlagcxCommContext*>(dev_ctx.GetCommContext());
+#else
+  distributed::NCCLCommContext* comm_ctx = nullptr;
+  comm_ctx =
+      static_cast<distributed::NCCLCommContext*>(dev_ctx.GetCommContext());
+#endif
+  PADDLE_ENFORCE_NE(comm_ctx,
+                    nullptr,
+                    common::errors::Unavailable(
+                        "NCCLCommContext is nullptr, collective op should "
+                        "has ring_id attr."));
+  stream = dev_ctx.stream();
+#if defined(PADDLE_WITH_FLAGCX) && defined(PADDLE_KERNEL_WITH_FLAGCX)
+  comm_ctx->AllGather(&temp_out, *x, reinterpret_cast<flagcxStream_t>(&stream));
+#else
+  comm_ctx->AllGather(&temp_out, *x, stream);
+#endif
+
+  std::vector<DenseTensor> inputs;
+  int axis = x->dims().size() - 1;
+  auto out_dims = x->dims();
+  out_dims[out_dims.size() - 1] *= nranks;
+  int64_t rows_per_tensor = x->dims()[0];
+  int64_t offset = 0;
+  for (int i = 0; i < nranks; i++) {
+    DenseTensor temp = temp_out.Slice(offset, offset + rows_per_tensor);
+    inputs.emplace_back(temp);
+    offset += rows_per_tensor;
+  }
+
+  funcs::ConcatFunctor<GPUContext, T> functor;
+  out->Resize(out_dims);
+  dev_ctx.template Alloc<T>(out);
+  functor(dev_ctx, inputs, axis, out);
+#else
+  PADDLE_THROW(common::errors::PreconditionNotMet(
+      "PaddlePaddle should compile with GPU."));
+#endif
+}
+}  // namespace phi
+
+PD_REGISTER_KERNEL(c_concat,
+                   GPU,
+                   ALL_LAYOUT,
+                   phi::CConcatKernel,
+                   float,
+                   double,
+                   int,
+                   int64_t,
+                   phi::bfloat16,
+                   phi::float16) {}