Example: Convert MKL Sparse Matrix-Vector Multiplication with CSR Matrices to AOCL-Sparse - 5.2 English - 68552

MKL call

mkl_?csrmv(const char *transa, const MKL_INT *m, const MKL_INT *k, const float *alpha,
  const char *matdescra, const float *val, const MKL_INT *indx, const MKL_INT *pntrb,
  const MKL_INT *pntre, const float *x, const float *beta, float *y)

Steps to convert into an AOCL-Sparse call

aoclsparse_?mv(aoclsparse_operation op, const float *alpha, aoclsparse_matrix A,
  const aoclsparse_mat_descr descr, const float *x, const float *beta, float *y)

1. Create a aoclsparse_matrix handle, A, using aoclsparse_create_?csr()

   // Create matrix A from m, k, val, indx, pntrb, pntre
   aoclsparse_matrix A;
   aoclsparse_index_base base = /* refer to Table 3 */;
   aoclsparse_int nnz;
   aoclsparse_int *row_ptr;
   aoclsparse_int *col_idx;
   aoclsparse_int i;
   aoclsparse_status status;
   
   nnz = pntre[*m-1] - pntrb[0];
   col_idx = (aoclsparse_int *) indx;
   
   // convert pntrb and pntre to row_ptr
   // assuming there is no gap between pntre[i] and pntrb[i+1]
   row_ptr[0] = base;
   for (i = 0; i < m; i++)
     row_ptr[i+1] = row_ptr[i] + pntre[i] - pntrb[i];
   
   status = aoclsparse_create_scsr(&A, base, *m, *n, nnz, row_ptr, col_idx, val);
   if (status != aoclsparse_status_success)
     return status;
   

2. Create a aoclsparse_mat_descr, descr, and configure it using aoclsparse_set_mat_type(), aoclsparse_set_mat_fill_mode(), aoclsparse_set_mat_diag_type(), and aoclsparse_set_mat_index_base(). Refer to Table 11.5 for parameter mappings.

   // create descr
   aoclsparse_mat_descr descr;
   status = aoclsparse_create_mat_descr(&descr);
   if (status != aoclsparse_status_success)
     return status;
   
   // fill in descr based on the values of the matdescra pointers
   aoclsparse_matrix_type mat_type = /* refer to Table 3 */;
   aoclsparse_fill_mode fill = /* refer to Table 3 */;
   aoclsparse_diag_type diag = /* refer to Table 3 */;
   aoclsparse_set_mat_index_base(descr, base);
   aoclsparse_set_mat_type(descr, mat_type);
   aoclsparse_set_mat_fill_mode(descr, fill);
   aoclsparse_set_mat_diag_type(descr, diag);
   

3. Call aoclsparse_?mv() for sparse matrix-vector multiplication

   // Map op to an appropriate value
   aoclsparse_operation op = /* refer to Table 3 */;
   
   // Call sparse matrix vector multiplication
   status = aoclsparse_smv(op, alpha, A, descr, x, beta, y);
   if (status != aoclsparse_status_success)
     return status;
   

4. Cleanup using aoclsparse_destroy_mat_descr() and aoclsparse_destroy()

   // descriptor
   aoclsparse_destroy_mat_descr(descr);
   
   // matrix
   aoclsparse_destroy(&A);