zsyrk(3P) Sun Performance Library zsyrk(3P)NAMEzsyrk - perform one of the symmetric rank k operations C :=
alpha*A*A' + beta*C or C := alpha*A'*A + beta*C
SYNOPSIS
SUBROUTINE ZSYRK(UPLO, TRANSA, N, K, ALPHA, A, LDA, BETA, C, LDC)
CHARACTER * 1 UPLO, TRANSA
DOUBLE COMPLEX ALPHA, BETA
DOUBLE COMPLEX A(LDA,*), C(LDC,*)
INTEGER N, K, LDA, LDC
SUBROUTINE ZSYRK_64(UPLO, TRANSA, N, K, ALPHA, A, LDA, BETA, C, LDC)
CHARACTER * 1 UPLO, TRANSA
DOUBLE COMPLEX ALPHA, BETA
DOUBLE COMPLEX A(LDA,*), C(LDC,*)
INTEGER*8 N, K, LDA, LDC
F95 INTERFACE
SUBROUTINE SYRK(UPLO, [TRANSA], [N], [K], ALPHA, A, [LDA], BETA, C,
[LDC])
CHARACTER(LEN=1) :: UPLO, TRANSA
COMPLEX(8) :: ALPHA, BETA
COMPLEX(8), DIMENSION(:,:) :: A, C
INTEGER :: N, K, LDA, LDC
SUBROUTINE SYRK_64(UPLO, [TRANSA], [N], [K], ALPHA, A, [LDA], BETA,
C, [LDC])
CHARACTER(LEN=1) :: UPLO, TRANSA
COMPLEX(8) :: ALPHA, BETA
COMPLEX(8), DIMENSION(:,:) :: A, C
INTEGER(8) :: N, K, LDA, LDC
C INTERFACE
#include <sunperf.h>
void zsyrk(char uplo, char transa, int n, int k, doublecomplex *alpha,
doublecomplex *a, int lda, doublecomplex *beta, doublecomplex
*c, int ldc);
void zsyrk_64(char uplo, char transa, long n, long k, doublecomplex
*alpha, doublecomplex *a, long lda, doublecomplex *beta, dou‐
blecomplex *c, long ldc);
PURPOSEzsyrk performs one of the symmetric rank k operations C := alpha*A*A' +
beta*C or C := alpha*A'*A + beta*C where alpha and beta are scalars,
C is an n by n symmetric matrix and A is an n by k matrix in the
first case and a k by n matrix in the second case.
ARGUMENTS
UPLO (input)
On entry, UPLO specifies whether the upper or lower
triangular part of the array C is to be referenced as
follows:
UPLO = 'U' or 'u' Only the upper triangular part of C is
to be referenced.
UPLO = 'L' or 'l' Only the lower triangular part of C is
to be referenced.
Unchanged on exit.
TRANSA (input)
On entry, TRANSA specifies the operation to be performed as
follows:
TRANSA = 'N' or 'n' C := alpha*A*A' + beta*C.
TRANSA = 'T' or 't' C := alpha*A'*A + beta*C.
Unchanged on exit.
TRANSA is defaulted to 'N' for F95 INTERFACE.
N (input)
On entry, N specifies the order of the matrix C. N must be
at least zero. Unchanged on exit.
K (input)
On entry with TRANSA = 'N' or 'n', K specifies the number
of columns of the matrix A, and on entry with
TRANSA = 'T' or 't', K specifies the number of rows of the
matrix A. K must be at least zero. Unchanged on exit.
ALPHA (input)
On entry, ALPHA specifies the scalar alpha. Unchanged on
exit.
A (input)
COMPLEX*16 array of DIMENSION ( LDA, ka ), where ka is
k when TRANSA = 'N' or 'n', and is n otherwise. Before
entry with TRANSA = 'N' or 'n', the leading n by k part
of the array A must contain the matrix A, otherwise the
leading k by n part of the array A must contain the
matrix A. Unchanged on exit.
LDA (input)
On entry, LDA specifies the first dimension of A as declared
in the calling (sub) program. When TRANSA = 'N' or 'n'
then LDA must be at least max( 1, n ), otherwise LDA must
be at least max( 1, k ). Unchanged on exit.
BETA (input)
On entry, BETA specifies the scalar beta. Unchanged on exit.
C (input/output)
COMPLEX*16 array of DIMENSION ( LDC, n ).
Before entry with UPLO = 'U' or 'u', the leading n by n
upper triangular part of the array C must contain the upper
triangular part of the symmetric matrix and the strictly
lower triangular part of C is not referenced. On exit, the
upper triangular part of the array C is overwritten by the
upper triangular part of the updated matrix.
Before entry with UPLO = 'L' or 'l', the leading n by n
lower triangular part of the array C must contain the lower
triangular part of the symmetric matrix and the strictly
upper triangular part of C is not referenced. On exit, the
lower triangular part of the array C is overwritten by the
lower triangular part of the updated matrix.
LDC (input)
On entry, LDC specifies the first dimension of C as declared
in the calling (sub) program. LDC must be at least
max( 1, n ). Unchanged on exit.
6 Mar 2009 zsyrk(3P)
