comparison ext/cblas/src/ddot.c @ 430:335af74a25b6

Merge from branch clapack-included

+/* ddot.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"
+
+doublereal ddot_(integer *n, doublereal *dx, integer *incx, doublereal *dy, 
+	integer *incy)
+{
+    /* System generated locals */
+    integer i__1;
+    doublereal ret_val;
+
+    /* Local variables */
+    integer i__, m, ix, iy, mp1;
+    doublereal dtemp;
+
+/*     .. 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 */
+    --dy;
+    --dx;
+
+    /* Function Body */
+    ret_val = 0.;
+    dtemp = 0.;
+    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__) {
+	dtemp += dx[ix] * dy[iy];
+	ix += *incx;
+	iy += *incy;
+/* L10: */
+    }
+    ret_val = dtemp;
+    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__) {
+	dtemp += dx[i__] * dy[i__];
+/* L30: */
+    }
+    if (*n < 5) {
+	goto L60;
+    }
+L40:
+    mp1 = m + 1;
+    i__1 = *n;
+    for (i__ = mp1; i__ <= i__1; i__ += 5) {
+	dtemp = dtemp + dx[i__] * dy[i__] + dx[i__ + 1] * dy[i__ + 1] + dx[
+		i__ + 2] * dy[i__ + 2] + dx[i__ + 3] * dy[i__ + 3] + dx[i__ + 
+		4] * dy[i__ + 4];
+/* L50: */
+    }
+L60:
+    ret_val = dtemp;
+    return ret_val;
+} /* ddot_ */