Abdelrahman Said
177 lines
4.1 KiB
C
177 lines
4.1 KiB
C
/* -- translated by f2c (version 20240504).
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You must link the resulting object file with libf2c:
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on Microsoft Windows system, link with libf2c.lib;
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on Linux or Unix systems, link with .../path/to/libf2c.a -lm
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or, if you install libf2c.a in a standard place, with -lf2c -lm
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-- in that order, at the end of the command line, as in
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cc *.o -lf2c -lm
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Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
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http://www.netlib.org/f2c/libf2c.zip
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*/
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#include "f2c.h"
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/* > \brief \b DAXPY
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=========== DOCUMENTATION ===========
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Online html documentation available at
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http://www.netlib.org/lapack/explore-html/
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Definition:
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===========
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SUBROUTINE DAXPY(N,DA,DX,INCX,DY,INCY)
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DOUBLE PRECISION DA
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INTEGER INCX,INCY,N
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DOUBLE PRECISION DX(*),DY(*)
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> \par Purpose:
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=============
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>
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> \verbatim
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>
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> DAXPY constant times a vector plus a vector.
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> uses unrolled loops for increments equal to one.
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> \endverbatim
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Arguments:
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==========
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> \param[in] N
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> \verbatim
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> N is INTEGER
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> number of elements in input vector(s)
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> \endverbatim
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>
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> \param[in] DA
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> \verbatim
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> DA is DOUBLE PRECISION
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> On entry, DA specifies the scalar alpha.
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> \endverbatim
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>
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> \param[in] DX
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> \verbatim
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> DX is DOUBLE PRECISION array, dimension ( 1 + ( N - 1 )*abs( INCX ) )
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> \endverbatim
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>
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> \param[in] INCX
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> \verbatim
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> INCX is INTEGER
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> storage spacing between elements of DX
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> \endverbatim
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>
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> \param[in,out] DY
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> \verbatim
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> DY is DOUBLE PRECISION array, dimension ( 1 + ( N - 1 )*abs( INCY ) )
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> \endverbatim
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>
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> \param[in] INCY
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> \verbatim
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> INCY is INTEGER
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> storage spacing between elements of DY
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> \endverbatim
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Authors:
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========
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> \author Univ. of Tennessee
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> \author Univ. of California Berkeley
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> \author Univ. of Colorado Denver
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> \author NAG Ltd.
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> \ingroup axpy
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> \par Further Details:
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=====================
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>
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> \verbatim
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>
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> jack dongarra, linpack, 3/11/78.
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> modified 12/3/93, array(1) declarations changed to array(*)
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> \endverbatim
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>
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=====================================================================
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Subroutine */ int igraphdaxpy_(integer *n, doublereal *da, doublereal *dx,
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integer *incx, doublereal *dy, integer *incy)
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{
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/* System generated locals */
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integer i__1;
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/* Local variables */
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integer i__, m, ix, iy, mp1;
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/* -- Reference BLAS level1 routine --
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-- Reference BLAS is a software package provided by Univ. of Tennessee, --
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-- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
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=====================================================================
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Parameter adjustments */
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--dy;
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--dx;
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/* Function Body */
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if (*n <= 0) {
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return 0;
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}
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if (*da == 0.) {
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return 0;
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}
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if (*incx == 1 && *incy == 1) {
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/* code for both increments equal to 1
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clean-up loop */
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m = *n % 4;
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if (m != 0) {
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i__1 = m;
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for (i__ = 1; i__ <= i__1; ++i__) {
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dy[i__] += *da * dx[i__];
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}
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}
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if (*n < 4) {
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return 0;
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}
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mp1 = m + 1;
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i__1 = *n;
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for (i__ = mp1; i__ <= i__1; i__ += 4) {
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dy[i__] += *da * dx[i__];
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dy[i__ + 1] += *da * dx[i__ + 1];
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dy[i__ + 2] += *da * dx[i__ + 2];
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dy[i__ + 3] += *da * dx[i__ + 3];
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}
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} else {
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/* code for unequal increments or equal increments
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not equal to 1 */
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ix = 1;
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iy = 1;
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if (*incx < 0) {
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ix = (-(*n) + 1) * *incx + 1;
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}
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if (*incy < 0) {
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iy = (-(*n) + 1) * *incy + 1;
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}
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i__1 = *n;
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for (i__ = 1; i__ <= i__1; ++i__) {
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dy[iy] += *da * dx[ix];
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ix += *incx;
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iy += *incy;
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}
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}
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return 0;
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/* End of DAXPY */
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} /* igraphdaxpy_ */
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