GEMM - SBS

General matrix multiplication functions for computing \( C \leftarrow \alpha A B + \beta C \) with stripe-block-stipe distribution.

  ------                     ------         ------
  |    |                     |    |         |    |
  |    |                     |    |         |    |
  ------                     ------         ------
  |    |       -------       |    |         |    |
  |    |       |  |  |       |    |         |    |
  ------   *   -------   +   ------   -->   ------
  |    |       |  |  |       |    |         |    |
  |    |       -------       |    |         |    |
  ------          B          ------         ------
  |    |                     |    |         |    |
  |    |                     |    |         |    |
  ------                     ------         ------
    A                          C              C

Functions

void pgemm_sbs(int mLocal, int n, int k, float alpha, const float *A, int lda, const float *B, int ldb, int bRowOffset, int bColOffset, MatrixDistribution &distB, float beta, float *C, int ldc, Context &ctx)

Computes a distributed general matrix multiplication of the form \( C \leftarrow \alpha A B + \beta C \) in single precision.

\(A\) and \(C\) are only split along the row dimension (stripes), while \(B\) can be distributed as any supported MatrixDistribution type.

Parameters

• mLocal – [in] Number rows of \(A\) and \(C\) stored at calling MPI rank. This number may differ for each rank.

• n – [in] Number of columns of \(B\).

• k – [in] Number of columns of \(C\) and rows of \(B\).

• alpha – [in] Scaling of multiplication of \(A^H\) and \(B\)

• A – [in] Pointer to matrix \(A\).

• lda – [in] Leading dimension of \(A\) with lda \(\geq\) kLocal.

• B – [in] Pointer to matrix \(B\).

• ldb – [in] Leading dimension of \(B\) with ldb \(\geq\) loc(k), where loc(k) is the number of locally stored rows of \(B\).

• bRowOffset – [in] Row offset in the global matrix \(B\), identifying the first row of the submatrix \(B\).

• bColOffset – [in] Column offset in the global matrix \(B\), identifying the first coloumn of the submatrix \(B\).

• distB – [in] Matrix distribution of global matrix \(B\).

• beta – [in] Scaling of \(C\) before summation.

• C – [out] Pointer to matrix \(C\).

• ldc – [in] Leading dimension of \(C\) with ldC \(\geq\) mLocal.

• ctx – [in] Context, which provides configuration settings and reusable resources.

void pgemm_sbs(int mLocal, int n, int k, double alpha, const double *A, int lda, const double *B, int ldb, int bRowOffset, int bColOffset, MatrixDistribution &distB, double beta, double *C, int ldc, Context &ctx)

Computes a distributed general matrix multiplication of the form \( C \leftarrow \alpha A B + \beta C \) in double precision.

See documentation above.

void pgemm_sbs(int mLocal, int n, int k, std::complex<float> alpha, const std::complex<float> *A, int lda, const std::complex<float> *B, int ldb, int bRowOffset, int bColOffset, MatrixDistribution &distB, std::complex<float> beta, std::complex<float> *C, int ldc, Context &ctx)

Computes a distributed general matrix multiplication of the form \( C \leftarrow \alpha A B + \beta C \) in double precision.

See documentation above.

void pgemm_sbs(int mLocal, int n, int k, std::complex<double> alpha, const std::complex<double> *A, int lda, const std::complex<double> *B, int ldb, int bRowOffset, int bColOffset, MatrixDistribution &distB, std::complex<double> beta, std::complex<double> *C, int ldc, Context &ctx)

Computes a distributed general matrix multiplication of the form \( C \leftarrow \alpha A B + \beta C \) in double precision.

See documentation above.