Developer Reference for Intel® oneAPI Math Kernel Library - C

Developer Reference

  • 0.9
  • 09/09/2020
  • Public Content
Contents

p?her2k

Performs a rank-2k update of a Hermitian distributed matrix.

Syntax

void pcher2k
(
const char
*uplo
,
const char
*trans
,
const MKL_INT
*n
,
const MKL_INT
*k
,
const MKL_Complex8
*alpha
,
const MKL_Complex8
*a
,
const MKL_INT
*ia
,
const MKL_INT
*ja
,
const MKL_INT
*desca
,
const MKL_Complex8
*b
,
const MKL_INT
*ib
,
const MKL_INT
*jb
,
const MKL_INT
*descb
,
const float
*beta
,
MKL_Complex8
*c
,
const MKL_INT
*ic
,
const MKL_INT
*jc
,
const MKL_INT
*descc
);
void pzher2k
(
const char
*uplo
,
const char
*trans
,
const MKL_INT
*n
,
const MKL_INT
*k
,
const MKL_Complex16
*alpha
,
const MKL_Complex16
*a
,
const MKL_INT
*ia
,
const MKL_INT
*ja
,
const MKL_INT
*desca
,
const MKL_Complex16
*b
,
const MKL_INT
*ib
,
const MKL_INT
*jb
,
const MKL_INT
*descb
,
const double
*beta
,
MKL_Complex16
*c
,
const MKL_INT
*ic
,
const MKL_INT
*jc
,
const MKL_INT
*descc
);
Include Files
  • mkl_pblas.h
Description
The
p?her2k
 routines perform a distributed matrix-matrix operation defined as 
sub(C):=alpha*sub(A)*conjg(sub(B)')+ conjg(alpha)*sub(B)*conjg(sub(A)')+beta*sub(C),
or 
sub(C):=alpha*conjg(sub(A)')*sub(A)+ conjg(alpha)*conjg(sub(B)')*sub(A) + beta*sub(C),
where:
alpha
 and
beta
 are scalars,
sub(
C
)
 is an
n
-by-
n
 Hermitian distributed matrix,
sub(
C
) = C(
ic
:
ic
+
n
-1,
jc
:
jc
+
n
-1)
.
sub(
A
)
 is a distributed matrix,
sub(
A
)=
A
(
ia
:
ia
+
n
-1,
ja
:
ja
+
k
-1)
, if
trans
 = '
N
'
 or
'
n
'
, and
sub(
A
) =
A
(
ia
:
ia
+
k
-1,
ja
:
ja
+
n
-1)
 otherwise.
sub(
B
)
 is a distributed matrix,
sub(
B
) =
B
(
ib
:
ib
+
n
-1,
jb
:
jb
+
k
-1)
, if
trans
 =
'N'
 or
'n'
, and
sub(
B
)=
B
(
ib
:
ib
+
k
-1,
jb
:
jb
+
n
-1)
 otherwise.
Input Parameters
uplo
(global) Specifies whether the upper or lower triangular part of the Hermitian distributed matrix
sub(
C
)
 is used:
If
uplo
 =
'U'
 or
'u'
, then the upper triangular part of the
sub(
C
)
 is used.
If
uplo
 =
'L'
 or
'l'
, then the low triangular part of the
sub(
C
)
 is used.
trans
(global) Specifies the operation:
if
trans
 =
'N'
 or
'n'
, then
sub(
C
) :=
alpha
*sub(
A
)*conjg(sub(
B
)')+ conjg(
alpha
)*sub(
B
)*conjg(sub(
A
)') +
beta
*sub(
C
)
;
if
trans
 =
'C'
 or
'c'
, then
sub(
C
) :=
alpha
*conjg(sub(
A
)')*sub(
A
)+ conjg(
alpha
)*conjg(sub(
B
)')*sub(
A
) +
beta
*sub(
C
)
.
n
(global) Specifies the order of the distributed matrix
sub(
C
)
,
n
≥
 0.
k
(global) On entry with
trans
 =
'N'
 or
'n'
,
k
 specifies the number of columns of the distributed matrices
sub(
A
)
 and
sub(
B
)
, and on entry with
trans
 =
'C'
 or
'c'
 ,
k
 specifies the number of rows of the distributed matrices
sub(
A
)
 and
sub(
B
)
,
k
≥
 0.
alpha
(global)
Specifies the scalar
alpha
.
a
(local)
Array, size
(
lld_a
,
kla
)
, where
kla
 is
LOCq(
ja
+
k
-1)
 when
trans
 =
'N'
 or
'n'
, and is
LOCq(
ja
+
n
-1)
 otherwise. Before entry with
trans
 =
'N'
 or
'n'
, this array contains the local pieces of the distributed matrix
sub(
A
)
.
ia
,
ja
(global) The row and column indices in the distributed matrix
A
 indicating the first row and the first column of the submatrix
sub(
A
)
, respectively.
desca
(global and local) array of dimension 9. The array descriptor of the distributed matrix
A
.
b
(local)
Array, size
(
lld_b
,
klb
)
, where
klb
 is
LOCq(
jb
+
k
-1)
 when
trans
 =
'N'
 or
'n'
, and is
LOCq(
jb
+
n
-1)
 otherwise. Before entry with
trans
 =
'N'
 or
'n'
, this array contains the local pieces of the distributed matrix
sub(
B
)
.
ib
,
jb
(global) The row and column indices in the distributed matrix
B
 indicating the first row and the first column of the submatrix
sub(
B
)
, respectively.
descb
(global and local) array of dimension 9. The array descriptor of the distributed matrix
B
.
beta
(global)
Specifies the scalar
beta
.
c
(local)
Array, size
(
lld_c
, LOCq(
jc
+
n
-1))
.
Before entry with
uplo
 =
'U'
 or
'u'
, this array contains
n
-by-
n
 upper triangular part of the symmetric distributed matrix
sub(
C
)
 and its strictly lower triangular part is not referenced.
Before entry with
uplo
 =
'L'
 or
'l'
, this array contains
n
-by-
n
 lower triangular part of the symmetric distributed matrix
sub(
C
)
 and its strictly upper triangular part is not referenced.
ic
,
jc
(global) The row and column indices in the distributed matrix
C
 indicating the first row and the first column of the submatrix
sub(
C
)
, respectively.
descc
(global and local) array of dimension 9. The array descriptor of the distributed matrix
C
.
Output Parameters
c
With
uplo
 =
'U'
 or
'u'
, the upper triangular part of
sub(
C
)
 is overwritten by the upper triangular part of the updated distributed matrix.
With
uplo
 =
'L'
 or
'l'
, the lower triangular part of
sub(
C
)
 is overwritten by the upper triangular part of the updated distributed 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