cher2(3P) Sun Performance Library cher2(3P)NAMEcher2 - perform the hermitian rank 2 operation A := alpha*x*conjg( y'
) + conjg( alpha )*y*conjg( x' ) + A
SYNOPSIS
SUBROUTINE CHER2(UPLO, N, ALPHA, X, INCX, Y, INCY, A, LDA)
CHARACTER * 1 UPLO
COMPLEX ALPHA
COMPLEX X(*), Y(*), A(LDA,*)
INTEGER N, INCX, INCY, LDA
SUBROUTINE CHER2_64(UPLO, N, ALPHA, X, INCX, Y, INCY, A, LDA)
CHARACTER * 1 UPLO
COMPLEX ALPHA
COMPLEX X(*), Y(*), A(LDA,*)
INTEGER*8 N, INCX, INCY, LDA
F95 INTERFACE
SUBROUTINE HER2(UPLO, [N], ALPHA, X, [INCX], Y, [INCY], A, [LDA])
CHARACTER(LEN=1) :: UPLO
COMPLEX :: ALPHA
COMPLEX, DIMENSION(:) :: X, Y
COMPLEX, DIMENSION(:,:) :: A
INTEGER :: N, INCX, INCY, LDA
SUBROUTINE HER2_64(UPLO, [N], ALPHA, X, [INCX], Y, [INCY], A, [LDA])
CHARACTER(LEN=1) :: UPLO
COMPLEX :: ALPHA
COMPLEX, DIMENSION(:) :: X, Y
COMPLEX, DIMENSION(:,:) :: A
INTEGER(8) :: N, INCX, INCY, LDA
C INTERFACE
#include <sunperf.h>
void cher2(char uplo, int n, complex *alpha, complex *x, int incx, com‐
plex *y, int incy, complex *a, int lda);
void cher2_64(char uplo, long n, complex *alpha, complex *x, long incx,
complex *y, long incy, complex *a, long lda);
PURPOSEcher2 performs the hermitian rank 2 operation A := alpha*x*conjg( y' )
+ conjg( alpha )*y*conjg( x' ) + A where alpha is a scalar, x and y are
n element vectors and A is an n by n hermitian matrix.
ARGUMENTS
UPLO (input)
On entry, UPLO specifies whether the upper or lower triangu‐
lar part of the array A is to be referenced as follows:
UPLO = 'U' or 'u' Only the upper triangular part of A is to
be referenced.
UPLO = 'L' or 'l' Only the lower triangular part of A is to
be referenced.
Unchanged on exit.
N (input)
On entry, N specifies the order of the matrix A. N >= 0.
Unchanged on exit.
ALPHA (input)
On entry, ALPHA specifies the scalar alpha. Unchanged on
exit.
X (input)
( 1 + ( n - 1 )*abs( INCX ) ). Before entry, the incremented
array X must contain the n element vector x. Unchanged on
exit.
INCX (input)
On entry, INCX specifies the increment for the elements of X.
INCX <> 0. Unchanged on exit.
Y (input)
( 1 + ( n - 1 )*abs( INCY ) ). Before entry, the incremented
array Y must contain the n element vector y. Unchanged on
exit.
INCY (input)
On entry, INCY specifies the increment for the elements of Y.
INCY <> 0. Unchanged on exit.
A (input/output)
Before entry with UPLO = 'U' or 'u', 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. On exit, the
upper triangular part of the array A 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 A must contain the lower triangular part of
the hermitian matrix and the strictly upper triangular part
of A is not referenced. On exit, the lower triangular part of
the array A is overwritten by the lower triangular part of
the updated matrix. Note that the imaginary parts of the
diagonal elements need not be set, they are assumed to be
zero, and on exit they are set to zero.
LDA (input)
On entry, LDA specifies the first dimension of A as declared
in the calling (sub) program. LDA >= max( 1, n ). Unchanged
on exit.
6 Mar 2009 cher2(3P)
