math_utils.hpp

// Copyright (c) "2019, by Stanford University
//               Developer: Mario Di Renzo
//               Affiliation: Center for Turbulence Research, Stanford University
//               URL: https://ctr.stanford.edu
//               Citation: Di Renzo, M., Lin, F., and Urzay, J. (2020).
//                         HTR solver: An open-source exascale-oriented task-based
//                         multi-GPU high-order code for hypersonic aerothermodynamics.
//                         Computer Physics Communications 255, 107262"
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//    * Redistributions of source code must retain the above copyright
//      notice, this list of conditions and the following disclaimer.
//    * Redistributions in binary form must reproduce the above copyright
//      notice, this list of conditions and the following disclaimer in the
//      documentation and/or other materials provided with the distribution.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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#ifndef __MATH_UTILS_HPP__
#define __MATH_UTILS_HPP__

#ifndef __CUDA_HD__
#ifdef __CUDACC__
#define __CUDA_HD__ __host__ __device__
#else
#define __CUDA_HD__
#endif
#endif

#ifndef __UNROLL__
#ifdef __CUDACC__
#define __UNROLL__ #pragma unroll
#else
#define __UNROLL__
#endif
#endif

__CUDA_HD__
inline double dot(const double *a, const double *b) {
   return a[0]*b[0] + a[1]*b[1] + a[2]*b[2];
}

template<int n>
__CUDA_HD__
inline void MatMul(const double *A, const double *x, double *r) {
   __UNROLL__
   for (int i=0; i<n; i++) {
      r[i] = 0.0;
      __UNROLL__
      for (int j=0; j<n; j++)
         r[i] += A[i*n+j]*x[j];
   }
}

#endif // __MATH_UTILS_HPP__