hemm¶
Computes a matrix-matrix product where one input matrix is Hermitian and one is general.
Syntax
void hemm(queue &exec_queue,
side left_right,
uplo upper_lower,
std::int64_t m,
std::int64_t n,
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)
hemm
supports the following precisions and devices:
T |
Devices Supported |
---|---|
|
Host, CPU, and GPU |
|
Host, CPU, and GPU |
Description
The hemm
routines compute a scalar-matrix-matrix product and add the result to a scalar-matrix product, where one of the matrices in the multiplication is Hermitian. The argument left_right
determines if the Hermitian matrix, A
, is on the left of the multiplication (left_right
= side::left
) or on the right (left_right
= side::right
). Depending on left_right
, the operation is defined as
C <- alpha*A*B + beta*C
or
C <- alpha*B*A + beta*C
where:
alpha
and beta
are scalars,
A
is a Hermitian matrix, either m
-by-m
or n
-by-n
matrices,
B
and C
are m
-by-n
matrices.
Input Parameters
- exec_queue
The queue where the routine should be executed.
- left_right
Specifies whether
A
is on the left side of the multiplication (side::left
) or on the right side (side::right
). See Data Types for more details.- uplo
Specifies whether
A
’s data is stored in its upper or lower triangle. See Data Types for more details.- m
Specifies the number of rows of the matrix
B
andC
.The value of
m
must be at least zero.- n
Specifies the number of columns of the matrix
B
andC
.The value of
n
must be at least zero.- alpha
Scaling factor for the matrix-matrix product.
- a
Buffer holding input matrix
A
. Must have size at leastlda
*m
ifA
is on the left of the multiplication, orlda
*n
ifA
is on the right. See Matrix Storage for more details.- lda
Leading dimension of
A
. Must be at leastm
ifA
is on the left of the multiplication, or at leastn
ifA
is on the right. Must be positive.- b
Buffer holding input matrix
B
. It must have a size of at least ldb*n if column major layout is used to store matrices or at least ldb*m if row major layout is used to store matrices. See Matrix Storage for more details.- ldb
Leading dimension of
B
. It must be positive and at least m if column major layout is used to store matrices or at least n if column major layout is used to store matrices.- beta
Scaling factor for matrix
C
.- c
Buffer holding input/output matrix
C
. It must have a size of at least ldc*n if column major layout is used to store matrices or at least ldc*m if row major layout is used to store matrices. See Matrix Storage for more details.- ldc
Leading dimension of
C
. It must be positive and at least m if column major layout is used to store matrices or at least n if column major layout is used to store matrices.
Output Parameters
- c
Output buffer, overwritten by
alpha
*A
*B
+beta
*C
(left_right
=side::left
) oralpha
*B
*A
+beta
*C
(left_right
=side::right
).
Note
If beta
= 0, matrix C
does not need to be initialized before calling hemm
.