mirror of
https://github.com/opencv/opencv.git
synced 2024-12-01 23:30:06 +08:00
84 lines
1.6 KiB
C
84 lines
1.6 KiB
C
#include "clapack.h"
|
|
|
|
/* Subroutine */ int dscal_(integer *n, doublereal *da, doublereal *dx,
|
|
integer *incx)
|
|
{
|
|
/* System generated locals */
|
|
integer i__1, i__2;
|
|
|
|
/* Local variables */
|
|
integer i__, m, mp1, nincx;
|
|
|
|
/* .. Scalar Arguments .. */
|
|
/* .. */
|
|
/* .. Array Arguments .. */
|
|
/* .. */
|
|
|
|
/* Purpose */
|
|
/* ======= */
|
|
/* * */
|
|
/* scales a vector by a constant. */
|
|
/* uses unrolled loops for increment equal to one. */
|
|
/* 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 */
|
|
if (*n <= 0 || *incx <= 0) {
|
|
return 0;
|
|
}
|
|
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) {
|
|
dx[i__] = *da * dx[i__];
|
|
/* L10: */
|
|
}
|
|
return 0;
|
|
|
|
/* code for increment equal to 1 */
|
|
|
|
|
|
/* clean-up loop */
|
|
|
|
L20:
|
|
m = *n % 5;
|
|
if (m == 0) {
|
|
goto L40;
|
|
}
|
|
i__2 = m;
|
|
for (i__ = 1; i__ <= i__2; ++i__) {
|
|
dx[i__] = *da * dx[i__];
|
|
/* L30: */
|
|
}
|
|
if (*n < 5) {
|
|
return 0;
|
|
}
|
|
L40:
|
|
mp1 = m + 1;
|
|
i__2 = *n;
|
|
for (i__ = mp1; i__ <= i__2; i__ += 5) {
|
|
dx[i__] = *da * dx[i__];
|
|
dx[i__ + 1] = *da * dx[i__ + 1];
|
|
dx[i__ + 2] = *da * dx[i__ + 2];
|
|
dx[i__ + 3] = *da * dx[i__ + 3];
|
|
dx[i__ + 4] = *da * dx[i__ + 4];
|
|
/* L50: */
|
|
}
|
|
return 0;
|
|
} /* dscal_ */
|