/* dswap.f -- translated by f2c (version 20061008). You must link the resulting object file with libf2c: on Microsoft Windows system, link with libf2c.lib; on Linux or Unix systems, link with .../path/to/libf2c.a -lm or, if you install libf2c.a in a standard place, with -lf2c -lm -- in that order, at the end of the command line, as in cc *.o -lf2c -lm Source for libf2c is in /netlib/f2c/libf2c.zip, e.g., http://www.netlib.org/f2c/libf2c.zip */ #include "f2c.h" #include "blaswrap.h" /* Subroutine */ int dswap_(integer *n, doublereal *dx, integer *incx, doublereal *dy, integer *incy) { /* System generated locals */ integer i__1; /* Local variables */ integer i__, m, ix, iy, mp1; doublereal dtemp; /* .. Scalar Arguments .. */ /* .. */ /* .. Array Arguments .. */ /* .. */ /* Purpose */ /* ======= */ /* interchanges two vectors. */ /* uses unrolled loops for increments equal one. */ /* jack dongarra, linpack, 3/11/78. */ /* modified 12/3/93, array(1) declarations changed to array(*) */ /* .. Local Scalars .. */ /* .. */ /* .. Intrinsic Functions .. */ /* .. */ /* Parameter adjustments */ --dy; --dx; /* Function Body */ 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; } i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { dtemp = dx[ix]; dx[ix] = dy[iy]; dy[iy] = dtemp; ix += *incx; iy += *incy; /* L10: */ } return 0; /* code for both increments equal to 1 */ /* clean-up loop */ L20: m = *n % 3; if (m == 0) { goto L40; } i__1 = m; for (i__ = 1; i__ <= i__1; ++i__) { dtemp = dx[i__]; dx[i__] = dy[i__]; dy[i__] = dtemp; /* L30: */ } if (*n < 3) { return 0; } L40: mp1 = m + 1; i__1 = *n; for (i__ = mp1; i__ <= i__1; i__ += 3) { dtemp = dx[i__]; dx[i__] = dy[i__]; dy[i__] = dtemp; dtemp = dx[i__ + 1]; dx[i__ + 1] = dy[i__ + 1]; dy[i__ + 1] = dtemp; dtemp = dx[i__ + 2]; dx[i__ + 2] = dy[i__ + 2]; dy[i__ + 2] = dtemp; /* L50: */ } return 0; } /* dswap_ */