gmres_kernel.h

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#ifndef __KRYLOV_GMRES_KERNEL_H__
#define __KRYLOV_GMRES_KERNEL_H__
/*
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     contributors may be used to endorse or promote products derived
     from this software without specific prior written permission.
 
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 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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*/
 
#include <math/bcknd/device/cuda/math_kernel.h>
 
template< typename T >
__global__ void gmres_part2_kernel(T  * __restrict__  w,
                                   T * const * __restrict__ v,
                                   const T * __restrict__ mult,
                                   const T * __restrict__ h,
                                   T * __restrict__ buf_h1,
                                   const int j,
                                   const int n) {
 
  const int idx = blockIdx.x * blockDim.x + threadIdx.x;
  const int str = blockDim.x * gridDim.x;
 
  const unsigned int lane = threadIdx.x % warpSize;
  const unsigned int wid = threadIdx.x / warpSize;
  
  __shared__ T shared[32];
  T tmp1 = 0.0;
 
  for (int i = idx; i < n; i+= str) {
    T tmp = 0.0;
    for (int k = 0; k < j; k ++) {
      tmp += -h[k]*v[k][i];
    }
    w[i] += tmp;
    tmp1 += w[i]*w[i]*mult[i];
  }
 
  tmp1 = reduce_warp<T>(tmp1);
  if (lane == 0)
    shared[wid] = tmp1;
  __syncthreads();
 
  tmp1 = (threadIdx.x < blockDim.x / warpSize) ? shared[lane] : 0;
  if (wid == 0)
    tmp1 = reduce_warp<T>(tmp1);
 
  if (threadIdx.x == 0)
    buf_h1[blockIdx.x] = tmp1;
 
}
 
 
 
#endif // __KRYLOV_GMRES_KERNEL_H__