Developer Reference for Intel® oneAPI Math Kernel Library - C

Developer Reference

  • 0.9
  • 09/09/2020
  • 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

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804