bicgstab_aux.cu

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/*
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#include <stdio.h>
#include "bicgstab_kernel.h"
#include <device/device_config.h>
#include <device/cuda/check.h>
#include <device/cuda/buffer.h>
 
#ifdef HAVE_NVSHMEM
#include <nvshmem.h>
#include <nvshmemx.h>
#endif
 
extern "C" {
 
#include <math/bcknd/device/device_mpi_reduce.h>
#include <math/bcknd/device/device_mpi_op.h>
 
#ifdef HAVE_NCCL
#include <math/bcknd/device/device_nccl_reduce.h>
#include <math/bcknd/device/device_nccl_op.h>
#endif
 
  cuda_buffer_t bicgstab_redbuf = CUDA_BUFFER_INIT_SYMM;
 
  static void bicgstab_reduce(real_xp *host, real_xp *dev, const int count,
                              cudaStream_t stream) {
#ifdef HAVE_NCCL
    device_nccl_allreduce(dev, dev, count, sizeof(real_xp),
                          DEVICE_NCCL_SUM, stream);
    CUDA_CHECK(cudaMemcpyAsync(host, dev, count * sizeof(real_xp),
                               cudaMemcpyDeviceToHost, stream));
    cudaStreamSynchronize(stream);
#elif HAVE_NVSHMEM
    if (sizeof(real_xp) == sizeof(float)) {
      nvshmemx_float_sum_reduce_on_stream(NVSHMEM_TEAM_WORLD, (float *) dev,
                                          (float *) dev, count, stream);
    }
    else if (sizeof(real_xp) == sizeof(double)) {
      nvshmemx_double_sum_reduce_on_stream(NVSHMEM_TEAM_WORLD, (double *) dev,
                                           (double *) dev, count, stream);
    }
    CUDA_CHECK(cudaMemcpyAsync(host, dev, count * sizeof(real_xp),
                               cudaMemcpyDeviceToHost, stream));
    cudaStreamSynchronize(stream);
#elif HAVE_DEVICE_MPI
    cudaStreamSynchronize(stream);
    device_mpi_allreduce(dev, host, count, sizeof(real_xp), DEVICE_MPI_SUM);
#else
    CUDA_CHECK(cudaMemcpyAsync(host, dev, count * sizeof(real_xp),
                               cudaMemcpyDeviceToHost, stream));
    cudaStreamSynchronize(stream);
#endif
  }
 
  void cuda_bicgstab_update_p(void *p, void *r, void *v, real *beta,
                              real *omega, int *n) {
 
    if (*n <= 0)
      return;
 
    const dim3 nthrds(1024, 1, 1);
    const dim3 nblcks(((*n) + 1024 - 1) / 1024, 1, 1);
    const cudaStream_t stream = (cudaStream_t) glb_cmd_queue;
 
    bicgstab_update_p_kernel<real>
      <<<nblcks, nthrds, 0, stream>>>((real *) p, (real *) r, (real *) v,
                                      *beta, *omega, *n);
    CUDA_CHECK(cudaGetLastError());
  }
 
  void cuda_bicgstab_product_and_norm(void *a, void *b, void *mult,
                                      real_xp *res, int *n) {
 
    const dim3 nthrds(1024, 1, 1);
    const dim3 nblcks(((*n) + 1024 - 1) / 1024, 1, 1);
    const int nb = ((*n) + 1024 - 1) / 1024;
    const cudaStream_t stream = (cudaStream_t) glb_cmd_queue;
 
    cuda_buffer_reserve(&bicgstab_redbuf,
                        2 * (nb > 1 ? nb : 1) * sizeof(real_xp));
    real_xp *host = (real_xp *) bicgstab_redbuf.host;
    real_xp *dev = (real_xp *) bicgstab_redbuf.dev;
 
    if (*n > 0) {
      bicgstab_product_and_norm_kernel<real, real_xp>
        <<<nblcks, nthrds, 0, stream>>>((real *) a, (real *) b, (real *) mult,
                                        dev, *n);
      CUDA_CHECK(cudaGetLastError());
      glsc3_reduce_kernel<real_xp><<<2, 1024, 0, stream>>>(dev, nb, 2);
      CUDA_CHECK(cudaGetLastError());
    }
    else {
      CUDA_CHECK(cudaMemsetAsync(dev, 0, 2 * sizeof(real_xp), stream));
    }
 
    bicgstab_reduce(host, dev, 2, stream);
    res[0] = host[0];
    res[1] = host[1];
  }
 
  real_xp cuda_bicgstab_part1(void *s, void *r, void *v, void *mult,
                              real *alpha, int *n) {
 
    const dim3 nthrds(1024, 1, 1);
    const dim3 nblcks(((*n) + 1024 - 1) / 1024, 1, 1);
    const int nb = ((*n) + 1024 - 1) / 1024;
    const cudaStream_t stream = (cudaStream_t) glb_cmd_queue;
 
    cuda_buffer_reserve(&bicgstab_redbuf,
                        2 * (nb > 1 ? nb : 1) * sizeof(real_xp));
    real_xp *host = (real_xp *) bicgstab_redbuf.host;
    real_xp *dev = (real_xp *) bicgstab_redbuf.dev;
 
    if (*n > 0) {
      bicgstab_part1_kernel<real, real_xp>
        <<<nblcks, nthrds, 0, stream>>>((real *) s, (real *) r, (real *) v,
                                        (real *) mult, dev, *alpha, *n);
      CUDA_CHECK(cudaGetLastError());
      reduce_kernel<real_xp><<<1, 1024, 0, stream>>>(dev, nb);
      CUDA_CHECK(cudaGetLastError());
    }
    else {
      CUDA_CHECK(cudaMemsetAsync(dev, 0, sizeof(real_xp), stream));
    }
 
    bicgstab_reduce(host, dev, 1, stream);
    return host[0];
  }
 
  void cuda_bicgstab_part2(void *x, void *r, void *p_hat, void *s_hat,
                           void *s, void *t, void *f, void *mult,
                           real *alpha, real *omega, real_xp *res, int *n) {
 
    const dim3 nthrds(1024, 1, 1);
    const dim3 nblcks(((*n) + 1024 - 1) / 1024, 1, 1);
    const int nb = ((*n) + 1024 - 1) / 1024;
    const cudaStream_t stream = (cudaStream_t) glb_cmd_queue;
 
    cuda_buffer_reserve(&bicgstab_redbuf,
                        2 * (nb > 1 ? nb : 1) * sizeof(real_xp));
    real_xp *host = (real_xp *) bicgstab_redbuf.host;
    real_xp *dev = (real_xp *) bicgstab_redbuf.dev;
 
    if (*n > 0) {
      bicgstab_part2_kernel<real, real_xp>
        <<<nblcks, nthrds, 0, stream>>>((real *) x, (real *) r,
                                        (real *) p_hat, (real *) s_hat,
                                        (real *) s, (real *) t, (real *) f,
                                        (real *) mult, dev,
                                        *alpha, *omega, *n);
      CUDA_CHECK(cudaGetLastError());
      glsc3_reduce_kernel<real_xp><<<2, 1024, 0, stream>>>(dev, nb, 2);
      CUDA_CHECK(cudaGetLastError());
    }
    else {
      CUDA_CHECK(cudaMemsetAsync(dev, 0, 2 * sizeof(real_xp), stream));
    }
 
    bicgstab_reduce(host, dev, 2, stream);
    res[0] = host[0];
    res[1] = host[1];
  }
}