c@427: /* dswap.f -- translated by f2c (version 20061008).
c@427:    You must link the resulting object file with libf2c:
c@427: 	on Microsoft Windows system, link with libf2c.lib;
c@427: 	on Linux or Unix systems, link with .../path/to/libf2c.a -lm
c@427: 	or, if you install libf2c.a in a standard place, with -lf2c -lm
c@427: 	-- in that order, at the end of the command line, as in
c@427: 		cc *.o -lf2c -lm
c@427: 	Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
c@427: 
c@427: 		http://www.netlib.org/f2c/libf2c.zip
c@427: */
c@427: 
c@427: #include "f2c.h"
c@427: #include "blaswrap.h"
c@427: 
c@427: /* Subroutine */ int dswap_(integer *n, doublereal *dx, integer *incx, 
c@427: 	doublereal *dy, integer *incy)
c@427: {
c@427:     /* System generated locals */
c@427:     integer i__1;
c@427: 
c@427:     /* Local variables */
c@427:     integer i__, m, ix, iy, mp1;
c@427:     doublereal dtemp;
c@427: 
c@427: /*     .. Scalar Arguments .. */
c@427: /*     .. */
c@427: /*     .. Array Arguments .. */
c@427: /*     .. */
c@427: 
c@427: /*  Purpose */
c@427: /*  ======= */
c@427: 
c@427: /*     interchanges two vectors. */
c@427: /*     uses unrolled loops for increments equal one. */
c@427: /*     jack dongarra, linpack, 3/11/78. */
c@427: /*     modified 12/3/93, array(1) declarations changed to array(*) */
c@427: 
c@427: 
c@427: /*     .. Local Scalars .. */
c@427: /*     .. */
c@427: /*     .. Intrinsic Functions .. */
c@427: /*     .. */
c@427:     /* Parameter adjustments */
c@427:     --dy;
c@427:     --dx;
c@427: 
c@427:     /* Function Body */
c@427:     if (*n <= 0) {
c@427: 	return 0;
c@427:     }
c@427:     if (*incx == 1 && *incy == 1) {
c@427: 	goto L20;
c@427:     }
c@427: 
c@427: /*       code for unequal increments or equal increments not equal */
c@427: /*         to 1 */
c@427: 
c@427:     ix = 1;
c@427:     iy = 1;
c@427:     if (*incx < 0) {
c@427: 	ix = (-(*n) + 1) * *incx + 1;
c@427:     }
c@427:     if (*incy < 0) {
c@427: 	iy = (-(*n) + 1) * *incy + 1;
c@427:     }
c@427:     i__1 = *n;
c@427:     for (i__ = 1; i__ <= i__1; ++i__) {
c@427: 	dtemp = dx[ix];
c@427: 	dx[ix] = dy[iy];
c@427: 	dy[iy] = dtemp;
c@427: 	ix += *incx;
c@427: 	iy += *incy;
c@427: /* L10: */
c@427:     }
c@427:     return 0;
c@427: 
c@427: /*       code for both increments equal to 1 */
c@427: 
c@427: 
c@427: /*       clean-up loop */
c@427: 
c@427: L20:
c@427:     m = *n % 3;
c@427:     if (m == 0) {
c@427: 	goto L40;
c@427:     }
c@427:     i__1 = m;
c@427:     for (i__ = 1; i__ <= i__1; ++i__) {
c@427: 	dtemp = dx[i__];
c@427: 	dx[i__] = dy[i__];
c@427: 	dy[i__] = dtemp;
c@427: /* L30: */
c@427:     }
c@427:     if (*n < 3) {
c@427: 	return 0;
c@427:     }
c@427: L40:
c@427:     mp1 = m + 1;
c@427:     i__1 = *n;
c@427:     for (i__ = mp1; i__ <= i__1; i__ += 3) {
c@427: 	dtemp = dx[i__];
c@427: 	dx[i__] = dy[i__];
c@427: 	dy[i__] = dtemp;
c@427: 	dtemp = dx[i__ + 1];
c@427: 	dx[i__ + 1] = dy[i__ + 1];
c@427: 	dy[i__ + 1] = dtemp;
c@427: 	dtemp = dx[i__ + 2];
c@427: 	dx[i__ + 2] = dy[i__ + 2];
c@427: 	dy[i__ + 2] = dtemp;
c@427: /* L50: */
c@427:     }
c@427:     return 0;
c@427: } /* dswap_ */