dgemv(3P) Sun Performance Library dgemv(3P)NAMEdgemv - perform one of the matrix-vector operations y := alpha*A*x +
beta*y or y := alpha*A'*x + beta*y
SYNOPSIS
SUBROUTINE DGEMV(TRANSA, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)
CHARACTER * 1 TRANSA
INTEGER M, N, LDA, INCX, INCY
DOUBLE PRECISION ALPHA, BETA
DOUBLE PRECISION A(LDA,*), X(*), Y(*)
SUBROUTINE DGEMV_64(TRANSA, M, N, ALPHA, A, LDA, X, INCX, BETA, Y,
INCY)
CHARACTER * 1 TRANSA
INTEGER*8 M, N, LDA, INCX, INCY
DOUBLE PRECISION ALPHA, BETA
DOUBLE PRECISION A(LDA,*), X(*), Y(*)
F95 INTERFACE
SUBROUTINE GEMV([TRANSA], [M], [N], ALPHA, A, [LDA], X, [INCX], BETA,
Y, [INCY])
CHARACTER(LEN=1) :: TRANSA
INTEGER :: M, N, LDA, INCX, INCY
REAL(8) :: ALPHA, BETA
REAL(8), DIMENSION(:) :: X, Y
REAL(8), DIMENSION(:,:) :: A
SUBROUTINE GEMV_64([TRANSA], [M], [N], ALPHA, A, [LDA], X, [INCX],
BETA, Y, [INCY])
CHARACTER(LEN=1) :: TRANSA
INTEGER(8) :: M, N, LDA, INCX, INCY
REAL(8) :: ALPHA, BETA
REAL(8), DIMENSION(:) :: X, Y
REAL(8), DIMENSION(:,:) :: A
C INTERFACE
#include <sunperf.h>
void dgemv(char transa, int m, int n, double alpha, double *a, int lda,
double *x, int incx, double beta, double *y, int incy);
void dgemv_64(char transa, long m, long n, double alpha, double *a,
long lda, double *x, long incx, double beta, double *y, long
incy);
PURPOSEdgemv performs one of the matrix-vector operations y := alpha*A*x +
beta*y, or y := alpha*A'*x + beta*y, where alpha and beta are scalars,
x and y are vectors and A is an m by n matrix.
ARGUMENTS
TRANSA (input)
On entry, TRANSA specifies the operation to be performed as
follows:
TRANSA = 'N' or 'n' y := alpha*A*x + beta*y.
TRANSA = 'T' or 't' y := alpha*A'*x + beta*y.
TRANSA = 'C' or 'c' y := alpha*A'*x + beta*y.
Unchanged on exit.
TRANSA is defaulted to 'N' for F95 INTERFACE.
M (input)
On entry, M specifies the number of rows of the matrix A. M
>= 0. Unchanged on exit.
N (input)
On entry, N specifies the number of columns of the matrix A.
N >= 0. Unchanged on exit.
ALPHA (input)
On entry, ALPHA specifies the scalar alpha. Unchanged on
exit.
A (input)
Before entry, the leading m by n part of the array A must
contain the matrix of coefficients. Unchanged on exit.
LDA (input)
On entry, LDA specifies the first dimension of A as declared
in the calling (sub) program. LDA >= max( 1, m ). Unchanged
on exit.
X (input)
( 1 + ( n - 1 )*abs( INCX ) ) when TRANSA = 'N' or 'n' and at
least ( 1 + ( m - 1 )*abs( INCX ) ) otherwise. Before entry,
the incremented array X must contain the vector x. Unchanged
on exit.
INCX (input)
On entry, INCX specifies the increment for the elements of X.
INCX <> 0. Unchanged on exit.
BETA (input)
On entry, BETA specifies the scalar beta. When BETA is sup‐
plied as zero then Y need not be set on input. Unchanged on
exit.
Y (input/output)
( 1 + ( m - 1 )*abs( INCY ) ) when TRANSA = 'N' or 'n' and at
least ( 1 + ( n - 1 )*abs( INCY ) ) otherwise. Before entry
with BETA non-zero, the incremented array Y must contain the
vector y. On exit, Y is overwritten by the updated vector y.
INCY (input)
On entry, INCY specifies the increment for the elements of Y.
INCY <> 0. Unchanged on exit.
6 Mar 2009 dgemv(3P)
