gemmt

Computes a matrix-matrix product with general matrices, but updates only the upper or lower triangular part of the result matrix.

Syntax

void gemmt(queue &exec_queue, uplo upper_lower, transpose transa, transpose transb, std::int64_t n, std::int64_t k, T alpha, buffer<T, 1> &a, std::int64_t lda, buffer<T, 1> &b, std::int64_t ldb, T beta, buffer<T, 1> &c, std::int64_t ldc)

gemmt supports the following precisions and devices.

T

Devices Supported

float

Host, CPU, and GPU

double

Host, CPU, and GPU

std::complex<float>

Host, CPU, and GPU

std::complex<double>

Host, CPU, and GPU

Description

The gemmt routines compute a scalar-matrix-matrix product and add the result to the upper or lower part of a scalar-matrix product, with general matrices. The operation is defined as:

C <- alpha*op(A)*op(B) + beta*C

where:

  • op(X) is one of op(X) = X, or op(X) = XT, or op(X) = XH

  • alpha and beta are scalars

  • A, B, and C are matrices

Here, op(A) is n x k, op(B) is k x n, and C is n x n.

Input Parameters

exec_queue

The queue where the routine should be executed.

upper_lower

Specifies whether C’s data is stored in its upper or lower triangle. See Data Types for more details.

transa

Specifies op(A), the transposition operation applied to A. See Data Types for more details.

transb

Specifies op(B), the transposition operation applied to B. See Data Types for more details.

n

Number of columns of op(A), columns of op(B), and columns ofC. Must be at least zero.

k

Number of columns of op(A) and rows of op(B). Must be at least zero.

alpha

Scaling factor for the matrix-matrix product.

a

Buffer holding the input matrix A.

If A is not transposed, A is an n-by-k matrix so the array a must have size at least lda*k.

If A is transposed, A is a k-by-n matrix so the array a must have size at least lda*n.

See Matrix Storage for more details.

lda

Leading dimension of A. Must be at least n if A is not transposed, and at least k if A is transposed. Must be positive.

b

Buffer holding the input matrix B.

If B is not transposed, B is a k-by-n matrix so the array b must have size at least ldb*n.

If B is transposed, B is an n-by-k matrix so the array b must have size at least ldb*k.

See Matrix Storage for more details.

ldb

Leading dimension of B. Must be at least k if B is not transposed, and at least n if B is transposed. Must be positive.

beta

Scaling factor for matrix C.

c

Buffer holding the input/output matrix C. Must have size at least ldc * n. See Matrix Storage for more details.

ldc

Leading dimension of C. Must be positive and at least m.

Output Parameters

c

Output buffer, overwritten by the upper or lower triangular part ofalpha*op(A)*op(B) + beta*C.

Notes

If beta = 0, matrix C does not need to be initialized before calling gemmt.