Contents

• NAME
• SYNOPSIS
  • F95 INTERFACE
  • C INTERFACE
• PURPOSE
• ARGUMENTS

NAME

     sgemv - perform one of the matrix-vector operations    y  :=
     alpha*A*x + beta*y or y := alpha*A'*x + beta*y

SYNOPSIS

     SUBROUTINE SGEMV(TRANSA, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)

     CHARACTER * 1 TRANSA
     INTEGER M, N, LDA, INCX, INCY
     REAL ALPHA, BETA
     REAL A(LDA,*), X(*), Y(*)

     SUBROUTINE SGEMV_64(TRANSA, M, N, ALPHA, A, LDA, X, INCX, BETA, Y,
           INCY)

     CHARACTER * 1 TRANSA
     INTEGER*8 M, N, LDA, INCX, INCY
     REAL ALPHA, BETA
     REAL 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 :: ALPHA, BETA
     REAL, DIMENSION(:) :: X, Y
     REAL, 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 :: ALPHA, BETA
     REAL, DIMENSION(:) :: X, Y
     REAL, DIMENSION(:,:) :: A

  C INTERFACE
     #include <sunperf.h>

     void sgemv(char transa, int m, int n, float alpha, float *a,
               int lda, float *x, int incx, float beta, float *y,
               int incy);
     void sgemv_64(char transa, long  m,  long  n,  float  alpha,
               float  *a,  long  lda,  float *x, long incx, float
               beta, float *y, long incy);

PURPOSE

     sgemv 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 supplied 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.