BLAS functions

1. Matrix operations
- 1.1. qmckl_dgemm

1 Matrix operations

1.1 `qmckl_dgemm`

Matrix multiply l\(C_{ij} = \beta C_{ij} + \alpha \sum_{k} A_{ik} \cdot B_{kj}\) using Fortran matmul function. TODO: Add description about the external library dependence.

qmckl_context	context	in	Global state
bool	TransA	in	Number of rows of the input matrix
bool	TransB	in	Number of rows of the input matrix
int64_t	m	in	Number of rows of the input matrix
int64_t	n	in	Number of columns of the input matrix
int64_t	k	in	Number of columns of the input matrix
double	alpha	in	Number of columns of the input matrix
double	A[][lda]	in	Array containing the \(m \times n\) matrix \(A\)
int64_t	lda	in	Leading dimension of array `A`
double	B[][ldb]	in	Array containing the \(n \times m\) matrix \(B\)
int64_t	ldb	in	Leading dimension of array `B`
double	beta	in	Array containing the \(n \times m\) matrix \(B\)
double	C[][ldc]	out	Array containing the \(n \times m\) matrix \(B\)
int64_t	ldc	in	Leading dimension of array `B`

1.1.1 Requirements

context is not QMCKL_NULL_CONTEXT
m > 0
n > 0
k > 0
lda >= m
ldb >= n
ldc >= n
A is allocated with at least \(m \times k \times 8\) bytes
B is allocated with at least \(k \times n \times 8\) bytes
C is allocated with at least \(m \times n \times 8\) bytes

1.1.2 C header

qmckl_exit_code qmckl_dgemm (
      const qmckl_context context,
      const bool TransA,
      const bool TransB,
      const int64_t m,
      const int64_t n,
      const int64_t k,
      const double alpha,
      const double* A,
      const int64_t lda,
      const double* B,
      const int64_t ldb,
      const double beta,
      double* const C,
      const int64_t ldc );

1.1.3 Source

integer function qmckl_dgemm_f(context, TransA, TransB, m, n, k, alpha, A, LDA, B, LDB, beta, C, LDC) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context)  , intent(in)  :: context
  logical*8  , intent(in)  :: TransA, TransB
  integer*8  , intent(in)  :: m, n, k
  real*8     , intent(in)  :: alpha, beta
  integer*8  , intent(in)  :: lda
  real*8     , intent(in)  :: A(m,k)
  integer*8  , intent(in)  :: ldb
  real*8     , intent(in)  :: B(k,n)
  integer*8  , intent(in)  :: ldc
  real*8     , intent(out) :: C(m,n)
  real*8, allocatable      :: AT(:,:), BT(:,:), CT(:,:)

  integer*8 :: i,j,l, LDA_2, LDB_2

  info = QMCKL_SUCCESS

  if (TransA) then
  allocate(AT(k,m))
    do i = 1, m
      do j = 1, k
        AT(j,i) = A(i,j)
      end do
    end do
  LDA_2 = M
  else
  LDA_2 = LDA
  endif

  if (TransB) then
  allocate(BT(n,k))
    do i = 1, k
      do j = 1, n
        BT(j,i) = B(i,j)
      end do
    end do
  LDB_2 = K
  else
  LDB_2 = LDB
  endif

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (m <= 0_8) then
     info = QMCKL_INVALID_ARG_4
     return
  endif

  if (n <= 0_8) then
     info = QMCKL_INVALID_ARG_5
     return
  endif

  if (k <= 0_8) then
     info = QMCKL_INVALID_ARG_6
     return
  endif

  if (LDA_2 .ne. m) then
     info = QMCKL_INVALID_ARG_9
     return
  endif

  if (LDB_2 .ne. k) then
     info = QMCKL_INVALID_ARG_10
     return
  endif

  if (LDC .ne. m) then
     info = QMCKL_INVALID_ARG_13
     return
  endif

   if (TransA) then
     C = matmul(AT,B)
   else if (TransB) then
     C = matmul(A,BT)
   else
     C = matmul(A,B)
   endif
end function qmckl_dgemm_f

BLAS functions

Table of Contents

1 Matrix operations

1.1 qmckl_dgemm

1.1.1 Requirements

1.1.2 C header

1.1.3 Source

1.1 `qmckl_dgemm`