/* sdot.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 "clapack.h" doublereal sdot_(integer *n, real *sx, integer *incx, real *sy, integer *incy) { /* System generated locals */ integer i__1; real ret_val; /* Local variables */ integer i__, m, ix, iy, mp1; real stemp; /* .. Scalar Arguments .. */ /* .. */ /* .. Array Arguments .. */ /* .. */ /* Purpose */ /* ======= */ /* forms the dot product of two vectors. */ /* uses unrolled loops for increments equal to one. */ /* jack dongarra, linpack, 3/11/78. */ /* modified 12/3/93, array(1) declarations changed to array(*) */ /* .. Local Scalars .. */ /* .. */ /* .. Intrinsic Functions .. */ /* .. */ /* Parameter adjustments */ --sy; --sx; /* Function Body */ stemp = 0.f; ret_val = 0.f; if (*n <= 0) { return ret_val; } 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__) { stemp += sx[ix] * sy[iy]; ix += *incx; iy += *incy; /* L10: */ } ret_val = stemp; return ret_val; /* code for both increments equal to 1 */ /* clean-up loop */ L20: m = *n % 5; if (m == 0) { goto L40; } i__1 = m; for (i__ = 1; i__ <= i__1; ++i__) { stemp += sx[i__] * sy[i__]; /* L30: */ } if (*n < 5) { goto L60; } L40: mp1 = m + 1; i__1 = *n; for (i__ = mp1; i__ <= i__1; i__ += 5) { stemp = stemp + sx[i__] * sy[i__] + sx[i__ + 1] * sy[i__ + 1] + sx[ i__ + 2] * sy[i__ + 2] + sx[i__ + 3] * sy[i__ + 3] + sx[i__ + 4] * sy[i__ + 4]; /* L50: */ } L60: ret_val = stemp; return ret_val; } /* sdot_ */