Fix bug of reduce_sum op. (#46045)

* Fix bug of reduce_sum op. When input.numel() > INT32_MAX, its result
is wrong.

* Fix some problems.
1. Change fluid head files to phi files.
2. Delete useless code.
3. Fix code style problems.

* Fix some code style problems.

* Fix some code style problems.

paddle/phi/kernels/kps/reduce_sum_kernel.cu

@@ -13,11 +13,60 @@
 // limitations under the License.
 
 #include "paddle/phi/kernels/reduce_sum_kernel.h"
+#include <limits>
+#include "paddle/phi/core/enforce.h"
 #include "paddle/phi/core/kernel_registry.h"
+#include "paddle/phi/kernels/funcs/eigen/common.h"
 #include "paddle/phi/kernels/gpu/reduce.h"
 
 namespace phi {
 
+template <typename T,
+          int EigenDimSize = 5,
+          int ReducedDimSize = 1,
+          bool ReduceAll = false>
+void ReduceSumEigen(const KPDevice& dev_ctx,
+                    const DenseTensor& x,
+                    bool reduce_all,
+                    const std::vector<int64_t>& dims,
+                    DataType out_dtype,
+                    DenseTensor* out,
+                    std::vector<int>* reduce_dims) {
+  // Resize Input Tensor
+  auto new_x = x;
+  int added_dims = EigenDimSize - x.dims().size();
+  std::array<int64_t, EigenDimSize> new_x_dim;
+  new_x_dim.fill(1);
+  for (int i = 0; i < x.dims().size(); i++) {
+    new_x_dim[i + added_dims] = x.dims().at(i);
+  }
+  new_x.Resize(phi::DDim(new_x_dim.data(), new_x_dim.size()));
+  auto eigen_x_tensor = EigenTensor<T, EigenDimSize>::From(new_x);
+
+  // Create Out Tensor
+  dev_ctx.Alloc<T>(out);
+  auto origin_out_dims = out->dims();
+  constexpr int kReduceOutRank = ReduceAll ? 1 : EigenDimSize - ReducedDimSize;
+  // Resize Out Tensor
+  std::array<int64_t, kReduceOutRank> new_out_dim;
+  new_out_dim.fill(1);
+  for (int i = 0; i < out->dims().size(); i++) {
+    new_out_dim[i + added_dims] = out->dims().at(i);
+  }
+  out->Resize(phi::DDim(new_out_dim.data(), new_out_dim.size()));
+
+  auto eigen_out_tensor = EigenTensor<T, kReduceOutRank>::From(*out);
+  for (int i = 0; i < ReducedDimSize; i++) {
+    (*reduce_dims)[i] += added_dims;
+  }
+  auto eigen_reduce_dim =
+      EigenDim<ReducedDimSize>::From(phi::make_ddim(*reduce_dims));
+  // Caculate
+  eigen_out_tensor.device(*dev_ctx.eigen_device()) =
+      eigen_x_tensor.sum(eigen_reduce_dim);
+  out->Resize(origin_out_dims);
+}
+
 template <typename T, typename Context>
 void SumRawKernel(const Context& dev_ctx,
                   const DenseTensor& x,
@@ -29,10 +78,65 @@ void SumRawKernel(const Context& dev_ctx,
   if (out_dtype == DataType::UNDEFINED && out->dtype() != x.dtype()) {
     out_dtype = out->dtype();
   }
-  phi::Reduce<T, kps::AddFunctor, kps::IdentityFunctor>(
-      dev_ctx, x, reduce_all, dims.GetData(), keep_dim, out_dtype, out);
-}
+  if (x.numel() > std::numeric_limits<int32_t>::max()) {
+#ifndef PADDLE_WITH_XPU_KP
+    if (out_dtype != phi::DataType::UNDEFINED && out_dtype != x.dtype()) {
+      PADDLE_THROW(phi::errors::Fatal(
+          "If Input.numel() > INT32_MAX, reduce_sum kernel uses EigenTensor "
+          "sum for reduce_sum function. As a result, input dtype should be "
+          "the same as out dtype"));
+    }
 
+    std::vector<int> reduce_dims = phi::funcs::details::GetReduceDim(
+        dims.GetData(), x.dims().size(), reduce_all);
+
+#define CALL_EIGEN_REDUCE_SUM_KERNEL(reduce_rank)              \
+  case reduce_rank: {                                          \
+    if (reduce_all) {                                          \
+      ReduceSumEigen<T, 5, reduce_rank, true>(dev_ctx,         \
+                                              x,               \
+                                              reduce_all,      \
+                                              dims.GetData(),  \
+                                              out_dtype,       \
+                                              out,             \
+                                              &reduce_dims);   \
+    } else {                                                   \
+      ReduceSumEigen<T, 5, reduce_rank, false>(dev_ctx,        \
+                                               x,              \
+                                               reduce_all,     \
+                                               dims.GetData(), \
+                                               out_dtype,      \
+                                               out,            \
+                                               &reduce_dims);  \
+    }                                                          \
+    break;                                                     \
+  }
+
+    switch (reduce_dims.size()) {
+      CALL_EIGEN_REDUCE_SUM_KERNEL(1);
+      CALL_EIGEN_REDUCE_SUM_KERNEL(2);
+      CALL_EIGEN_REDUCE_SUM_KERNEL(3);
+      CALL_EIGEN_REDUCE_SUM_KERNEL(4);
+      CALL_EIGEN_REDUCE_SUM_KERNEL(5);
+      default:
+        PADDLE_THROW(phi::errors::Fatal(
+            "If Input.numel() > INT32_MAX, reduce_sum kernel uses EigenTensor "
+            "sum for reduce_sum function. As a result, its dim should be <= "
+            "5."));
+        break;
+    }
+#undef CALL_EIGEN_REDUCE_SUM_KERNEL
+#else
+    PADDLE_THROW(phi::errors::Fatal(
+        "If Input.numel() > INT32_MAX, reduce_sum kernel uses EigenTensor "
+        "sum for reduce_sum function. Such case is only supported on GPU "
+        "now."));
+#endif
+  } else {
+    phi::Reduce<T, kps::AddFunctor, kps::IdentityFunctor>(
+        dev_ctx, x, reduce_all, dims.GetData(), keep_dim, out_dtype, out);
+  }
+}
 }  // namespace phi
 
 #ifdef PADDLE_WITH_XPU_KP