code: def _cupy_batched_unpack_params():
      return chainer.cuda.raw(
          r"""
  #include <cupy/carray.cuh>
  #define NCCL_FLOAT16  6
  #define NCCL_FLOAT32  7
  #define NCCL_FLOAT64  8
      extern "C" __global__
      void cupy_batched_unpack_params(
              void *src0, int src_dtype, int n_elems,
              unsigned long *params_dptr, int *params_dtype,
              int *params_size_csum, int n_params) {
          int tid = threadIdx.x + blockIdx.x * blockDim.x;
          if (tid >= n_elems) return;
          int j_min = 0;
          int j_max = n_params - 1;
          int j;
          while (1) {
              j = (j_min + j_max) / 2;
              if (tid < params_size_csum[j]) {
                  j_max = j - 1;
                  continue;
              }
              if (tid >= params_size_csum[j+1]){
                  j_min = j + 1;
                  continue;
              }
              break;
          }
          assert(tid >= params_size_csum[j]);
          assert(tid < params_size_csum[j+1]);
          int dst_dtype = params_dtype[j];
          int dst_idx = tid - params_size_csum[j];
          if (src_dtype == NCCL_FLOAT16) {
              half* src = (half*) src0;
              if (dst_dtype == NCCL_FLOAT16) {
                  ((half*) (params_dptr[j]))[dst_idx] = (half) src[tid];
              }
              else if (dst_dtype == NCCL_FLOAT32) {
                  ((float*) (params_dptr[j]))[dst_idx] = (float) src[tid];
              }
              else if (dst_dtype == NCCL_FLOAT64) {
                  ((double*) (params_dptr[j]))[dst_idx] = (double) src[tid];
              }
          }
          else if (src_dtype == NCCL_FLOAT32) {
              float* src = (float*) src0;
              if (dst_dtype == NCCL_FLOAT16) {
                  ((half*) (params_dptr[j]))[dst_idx] = (half) src[tid];
              }
              else if (dst_dtype == NCCL_FLOAT32) {
                  ((float*) (params_dptr[j]))[dst_idx] = (float) src[tid];
              }
              else if (dst_dtype == NCCL_FLOAT64) {
                  ((double*) (params_dptr[j]))[dst_idx] = (double) src[tid];
              }
         }
         else if (src_dtype == NCCL_FLOAT64) {
              double* src = (double*) src0;
              if (dst_dtype == NCCL_FLOAT16) {
                  ((half*) (params_dptr[j]))[dst_idx] = (half) src[tid];
              }
              else if (dst_dtype == NCCL_FLOAT32) {
                  ((float*) (params_dptr[j]))[dst_idx] = (float) src[tid];
              }
              else if (dst_dtype == NCCL_FLOAT64) {
                  ((double*) (params_dptr[j]))[dst_idx] = (double) src[tid];
              }
         }
      }""",
          "cupy_batched_unpack_params",
      )
  
imports: import ctypes
  import mpi4py.MPI
  import numpy
  from chainermn.communicators import _communication_utility
  import chainer.backends
  import chainerx
label_desc: Use image node_id 12 for calling a global function with example usage: _cupy_batched_unpack_params() and returns: chainer