hypre/blas/drot.c
2007-11-13 17:40:07 +00:00

104 lines
2.7 KiB
C

/*BHEADER**********************************************************************
* Copyright (c) 2007, Lawrence Livermore National Security, LLC.
* Produced at the Lawrence Livermore National Laboratory.
* Written by the HYPRE team. UCRL-CODE-222953.
* All rights reserved.
*
* This file is part of HYPRE (see http://www.llnl.gov/CASC/hypre/).
* Please see the COPYRIGHT_and_LICENSE file for the copyright notice,
* disclaimer, contact information and the GNU Lesser General Public License.
*
* HYPRE is free software; you can redistribute it and/or modify it under the
* terms of the GNU General Public License (as published by the Free Software
* Foundation) version 2.1 dated February 1999.
*
* HYPRE is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the IMPLIED WARRANTY OF MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the terms and conditions of the GNU General
* Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* $Revision$
***********************************************************************EHEADER*/
/* -- translated by f2c (version 19940927).
You must link the resulting object file with the libraries:
-lf2c -lm (in that order)
*/
#include "f2c.h"
#include "hypre_blas.h"
/* Subroutine */ int drot_(integer *n, doublereal *dx, integer *incx,
doublereal *dy, integer *incy, doublereal *c, doublereal *s)
{
/* System generated locals */
/* Local variables */
static integer i;
static doublereal dtemp;
static integer ix, iy;
/* applies a plane rotation.
jack dongarra, linpack, 3/11/78.
modified 12/3/93, array(1) declarations changed to array(*)
Parameter adjustments
Function Body */
#define DY(I) dy[(I)-1]
#define DX(I) dx[(I)-1]
if (*n <= 0) {
return 0;
}
if (*incx == 1 && *incy == 1) {
goto L20;
}
/* code for unequal increments or equal increments not equal
to 1 */
ix = 1;
iy = 1;
if (*incx < 0) {
ix = (-(*n) + 1) * *incx + 1;
}
if (*incy < 0) {
iy = (-(*n) + 1) * *incy + 1;
}
for (i = 1; i <= *n; ++i) {
dtemp = *c * DX(ix) + *s * DY(iy);
DY(iy) = *c * DY(iy) - *s * DX(ix);
DX(ix) = dtemp;
ix += *incx;
iy += *incy;
/* L10: */
}
return 0;
/* code for both increments equal to 1 */
L20:
for (i = 1; i <= *n; ++i) {
dtemp = *c * DX(i) + *s * DY(i);
DY(i) = *c * DY(i) - *s * DX(i);
DX(i) = dtemp;
/* L30: */
}
return 0;
} /* drot_ */