#include "kernel_Point_update_step.h"
#include "memops.cuh"
#include <cooperative_groups.h>
#include <cooperative_groups/details/partitioning.h>
#include <cooperative_groups/memcpy_async.h>
#include <cooperative_groups/reduce.h>
#include <cuda_runtime.h>

namespace cg = cooperative_groups;

namespace caspar {

__global__ void __launch_bounds__(1024, 1)
    PointUpdateStepKernel(double* Point_step_k,
                          unsigned int Point_step_k_num_alloc,
                          double* Point_p_kp1,
                          unsigned int Point_p_kp1_num_alloc,
                          const double* const alpha,
                          double* out_Point_step_kp1,
                          unsigned int out_Point_step_kp1_num_alloc,
                          size_t problem_size) {
  const int global_thread_idx = blockIdx.x * blockDim.x + threadIdx.x;
  __shared__ uint8_t inout_shared[8192];

  double r0, r1, r2, r3, r4;

  if (global_thread_idx < problem_size) {
    ReadIdx2<1024, double, double, double2>(
        Point_step_k, 0 * Point_step_k_num_alloc, global_thread_idx, r0, r1);
    ReadIdx2<1024, double, double, double2>(
        Point_p_kp1, 0 * Point_p_kp1_num_alloc, global_thread_idx, r2, r3);
  };
  LoadUnique<1, double, double>(alpha, 0, (double*)inout_shared);
  if (global_thread_idx < problem_size) {
    ReadShared1<double>((double*)inout_shared, 0, r4);
  };
  __syncthreads();
  if (global_thread_idx < problem_size) {
    r2 = fma(r2, r4, r0);
    r3 = fma(r3, r4, r1);
    WriteIdx2<1024, double, double, double2>(out_Point_step_kp1,
                                             0 * out_Point_step_kp1_num_alloc,
                                             global_thread_idx,
                                             r2,
                                             r3);
    ReadIdx1<1024, double, double, double>(
        Point_step_k, 2 * Point_step_k_num_alloc, global_thread_idx, r3);
    ReadIdx1<1024, double, double, double>(
        Point_p_kp1, 2 * Point_p_kp1_num_alloc, global_thread_idx, r2);
    r4 = fma(r2, r4, r3);
    WriteIdx1<1024, double, double, double>(out_Point_step_kp1,
                                            2 * out_Point_step_kp1_num_alloc,
                                            global_thread_idx,
                                            r4);
  };
}

void PointUpdateStep(double* Point_step_k,
                     unsigned int Point_step_k_num_alloc,
                     double* Point_p_kp1,
                     unsigned int Point_p_kp1_num_alloc,
                     const double* const alpha,
                     double* out_Point_step_kp1,
                     unsigned int out_Point_step_kp1_num_alloc,
                     size_t problem_size) {
  if (problem_size == 0) {
    return;
  }

  const int n_blocks = (problem_size + 1024 - 1) / 1024;
  PointUpdateStepKernel<<<n_blocks, 1024>>>(Point_step_k,
                                            Point_step_k_num_alloc,
                                            Point_p_kp1,
                                            Point_p_kp1_num_alloc,
                                            alpha,
                                            out_Point_step_kp1,
                                            out_Point_step_kp1_num_alloc,
                                            problem_size);
}

}  // namespace caspar