opencv/3rdparty/lapack/dasum.c

89 lines
1.8 KiB
C

#include "clapack.h"
doublereal dasum_(integer *n, doublereal *dx, integer *incx)
{
/* System generated locals */
integer i__1, i__2;
doublereal ret_val, d__1, d__2, d__3, d__4, d__5, d__6;
/* Local variables */
integer i__, m, mp1;
doublereal dtemp;
integer nincx;
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* takes the sum of the absolute values. */
/* jack dongarra, linpack, 3/11/78. */
/* modified 3/93 to return if incx .le. 0. */
/* modified 12/3/93, array(1) declarations changed to array(*) */
/* .. Local Scalars .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* Parameter adjustments */
--dx;
/* Function Body */
ret_val = 0.;
dtemp = 0.;
if (*n <= 0 || *incx <= 0) {
return ret_val;
}
if (*incx == 1) {
goto L20;
}
/* code for increment not equal to 1 */
nincx = *n * *incx;
i__1 = nincx;
i__2 = *incx;
for (i__ = 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) {
dtemp += (d__1 = dx[i__], abs(d__1));
/* L10: */
}
ret_val = dtemp;
return ret_val;
/* code for increment equal to 1 */
/* clean-up loop */
L20:
m = *n % 6;
if (m == 0) {
goto L40;
}
i__2 = m;
for (i__ = 1; i__ <= i__2; ++i__) {
dtemp += (d__1 = dx[i__], abs(d__1));
/* L30: */
}
if (*n < 6) {
goto L60;
}
L40:
mp1 = m + 1;
i__2 = *n;
for (i__ = mp1; i__ <= i__2; i__ += 6) {
dtemp = dtemp + (d__1 = dx[i__], abs(d__1)) + (d__2 = dx[i__ + 1],
abs(d__2)) + (d__3 = dx[i__ + 2], abs(d__3)) + (d__4 = dx[i__
+ 3], abs(d__4)) + (d__5 = dx[i__ + 4], abs(d__5)) + (d__6 =
dx[i__ + 5], abs(d__6));
/* L50: */
}
L60:
ret_val = dtemp;
return ret_val;
} /* dasum_ */