Developer Reference

  • 2021.1
  • 12/04/2020
  • Public Content
Contents

cblas_?hemm

Computes a matrix-matrix product where one input matrix is Hermitian.

Syntax

void
cblas_chemm
(
const
CBLAS_LAYOUT
Layout
,
const
CBLAS_SIDE
side
,
const
CBLAS_UPLO
uplo
,
const
MKL_INT
m
,
const
MKL_INT
n
,
const
void
*alpha
,
const
void
*a
,
const
MKL_INT
lda
,
const
void
*b
,
const
MKL_INT
ldb
,
const
void
*beta
,
void
*c
,
const
MKL_INT
ldc
);
void
cblas_zhemm
(
const
CBLAS_LAYOUT
Layout
,
const
CBLAS_SIDE
side
,
const
CBLAS_UPLO
uplo
,
const
MKL_INT
m
,
const
MKL_INT
n
,
const
void
*alpha
,
const
void
*a
,
const
MKL_INT
lda
,
const
void
*b
,
const
MKL_INT
ldb
,
const
void
*beta
,
void
*c
,
const
MKL_INT
ldc
);
Include Files
  • mkl.h
Description
The
?hemm
routines compute a scalar-matrix-matrix product using a Hermitian matrix
A
and a general matrix
B
and add the result to a scalar-matrix product using a general matrix
C
. 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,
B
and
C
are
m
-by-
n
matrices.
Input Parameters
Layout
Specifies whether two-dimensional array storage is row-major (
CblasRowMajor
) or column-major (
CblasColMajor
).
side
Specifies whether the Hermitian matrix
A
appears on the left or right in the operation as follows:
if
side
=
CblasLeft
, then
C
:=
alpha
*
A
*
B
+
beta
*
C
;
if
side
=
CblasRight
, then
C
:=
alpha
*
B
*
A
+
beta
*
C
.
uplo
Specifies whether the upper or lower triangular part of the Hermitian matrix
A
is used:
If
uplo
=
CblasUpper
, then the upper triangular part of the Hermitian matrix
A
is used.
If
uplo
=
CblasLower
, then the low triangular part of the Hermitian matrix
A
is used.
m
Specifies the number of rows of the matrix
C
.
The value of
m
must be at least zero.
n
Specifies the number of columns of the matrix
C
.
The value of
n
must be at least zero.
alpha
Specifies the scalar
alpha
.
a
Array, size
lda
*
ka
, where
ka
is
m
when
side
=
CblasLeft
and is
n
otherwise. Before entry with
side
=
CblasLeft
, the
m
-by-
m
part of the array
a
must contain the Hermitian matrix, such that when
uplo
=
CblasUpper
, the leading
m
-by-
m
upper triangular part of the array
a
must contain the upper triangular part of the Hermitian matrix and the strictly lower triangular part of
a
is not referenced, and when
uplo
=
CblasLower
, the leading
m
-by-
m
lower triangular part of the array
a
must contain the lower triangular part of the Hermitian matrix, and the strictly upper triangular part of
a
is not referenced.
Before entry with
side
=
CblasRight
, the
n
-by-
n
part of the array
a
must contain the Hermitian matrix, such that when
uplo
=
CblasUpper
, the leading
n
-by-
n
upper triangular part of the array
a
must contain the upper triangular part of the Hermitian matrix and the strictly lower triangular part of
a
is not referenced, and when
uplo
=
CblasLower
, the leading
n
-by-
n
lower triangular part of the array
a
must contain the lower triangular part of the Hermitian matrix, and the strictly upper triangular part of
a
is not referenced. The imaginary parts of the diagonal elements need not be set, they are assumed to be zero.
lda
Specifies the leading dimension of
a
as declared in the calling (sub) program. When
side
=
CblasLeft
then
lda
must be at least
max(1,
m
)
, otherwise
lda
must be at least
max(1,
n
)
.
b
For
Layout
=
CblasColMajor
: array, size
ldb
*
n
.
The leading
m
-by-
n
part of the array
b
must contain the matrix
B
.
For
Layout
=
CblasRowMajor
: array, size
ldb
*
m
. The leading
n
-by-
m
part of the array
b
must contain the matrix
B
ldb
Specifies the leading dimension of
b
as declared in the calling (sub)program.
When
Layout
=
CblasColMajor
,
ldb
must be at least
max(1,
m
)
; otherwise,
ldb
must be at least
max(1,
n
)
.
beta
Specifies the scalar
beta
.
When
beta
is supplied as zero, then
c
need not be set on input.
c
For
Layout
=
CblasColMajor
: array, size
ldc
*
n
. Before entry, the leading
m
-by-
n
part of the array
c
must contain the matrix
C
, except when
beta
is zero, in which case
c
need not be set on entry.
For
Layout
=
CblasRowMajor
: array, size
ldc
*
m
. Before entry, the leading
n
-by-
m
part of the array
c
must contain the matrix
C
, except when
beta
is zero, in which case
c
need not be set on entry.
ldc
Specifies the leading dimension of
c
as declared in the calling (sub)program.
When
Layout
=
CblasColMajor
,
ldc
must be at least
max(1,
m
)
; otherwise,
ldc
must be at least
max(1,
n
)
.
Output Parameters
c
Overwritten by the
m
-by-
n
updated matrix.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.