
DSYMM(l) BLAS routine DSYMM(l)
NAME
DSYMM  perform one of the matrixmatrix operations C := alpha*A*B + beta*C,
SYNOPSIS
SUBROUTINE DSYMM ( SIDE, UPLO, M, N, ALPHA, A, LDA, B, LDB, BETA, C, LDC )
CHARACTER*1 SIDE, UPLO
INTEGER M, N, LDA, LDB, LDC
DOUBLE PRECISION ALPHA, BETA
DOUBLE PRECISION A( LDA, * ), B( LDB, * ), C( LDC, * )
PURPOSE
DSYMM performs one of the matrixmatrix operations
or
C := alpha*B*A + beta*C,
where alpha and beta are scalars, A is a symmetric matrix and B and C are m by n matri
ces.
PARAMETERS
SIDE  CHARACTER*1.
On entry, SIDE specifies whether the symmetric matrix A appears on the left
or right in the operation as follows:
SIDE = 'L' or 'l' C := alpha*A*B + beta*C,
SIDE = 'R' or 'r' C := alpha*B*A + beta*C,
Unchanged on exit.
UPLO  CHARACTER*1.
On entry, UPLO specifies whether the upper or lower triangular part of
the symmetric matrix A is to be referenced as follows:
UPLO = 'U' or 'u' Only the upper triangular part of the symmetric matrix is to be
referenced.
UPLO = 'L' or 'l' Only the lower triangular part of the symmetric matrix is to be
referenced.
Unchanged on exit.
M  INTEGER.
On entry, M specifies the number of rows of the matrix C. M must be at least
zero. Unchanged on exit.
N  INTEGER.
On entry, N specifies the number of columns of the matrix C. N must be at least
zero. Unchanged on exit.
ALPHA  DOUBLE PRECISION.
On entry, ALPHA specifies the scalar alpha. Unchanged on exit.
A  DOUBLE PRECISION array of DIMENSION ( LDA, ka ), where ka is
m when SIDE = 'L' or 'l' and is n otherwise. Before entry with SIDE = 'L' or
'l', the m by m part of the array A must contain the symmetric matrix, such
that when UPLO = 'U' or 'u', the leading m by m upper triangular part of the array
A must contain the upper triangular part of the symmetric matrix and the
strictly lower triangular part of A is not referenced, and when UPLO = 'L' or
'l', the leading m by m lower triangular part of the array A must contain
the lower triangular part of the symmetric matrix and the strictly upper trian
gular part of A is not referenced. Before entry with SIDE = 'R' or 'r', the
n by n part of the array A must contain the symmetric matrix, such that when
UPLO = 'U' or 'u', the leading n by n upper triangular part of the array A must
contain the upper triangular part of the symmetric matrix and the strictly lower
triangular part of A is not referenced, and when UPLO = 'L' or 'l', the leading
n by n lower triangular part of the array A must contain the lower triangu
lar part of the symmetric matrix and the strictly upper triangular part of A
is not referenced. Unchanged on exit.
LDA  INTEGER.
On entry, LDA specifies the first dimension of A as declared in the calling (sub)
program. When SIDE = 'L' or 'l' then LDA must be at least max( 1, m ), other
wise LDA must be at least max( 1, n ). Unchanged on exit.
B  DOUBLE PRECISION array of DIMENSION ( LDB, n ).
Before entry, the leading m by n part of the array B must contain the matrix B.
Unchanged on exit.
LDB  INTEGER.
On entry, LDB specifies the first dimension of B as declared in the calling
(sub) program. LDB must be at least max( 1, m ). Unchanged on exit.
BETA  DOUBLE PRECISION.
On entry, BETA specifies the scalar beta. When BETA is supplied as zero then
C need not be set on input. Unchanged on exit.
C  DOUBLE PRECISION array of DIMENSION ( 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. On exit, the
array C is overwritten by the m by n updated matrix.
LDC  INTEGER.
On entry, LDC specifies the first dimension of C as declared in the calling
(sub) program. LDC must be at least max( 1, m ). Unchanged on exit.
Level 3 Blas routine.
 Written on 8February1989. Jack Dongarra, Argonne National Laboratory. Iain
Duff, AERE Harwell. Jeremy Du Croz, Numerical Algorithms Group Ltd. Sven Hammar
ling, Numerical Algorithms Group Ltd.
BLAS routine 16 October 1992 DSYMM(l) 
