89 lines
1.9 KiB
C
89 lines
1.9 KiB
C
#include "clapack.h"
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doublereal sasum_(integer *n, real *sx, integer *incx)
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{
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/* System generated locals */
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integer i__1, i__2;
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real ret_val, r__1, r__2, r__3, r__4, r__5, r__6;
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/* Local variables */
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integer i__, m, mp1, nincx;
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real stemp;
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/* .. Scalar Arguments .. */
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/* .. */
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/* .. Array Arguments .. */
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/* .. */
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/* Purpose */
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/* ======= */
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/* takes the sum of the absolute values. */
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/* uses unrolled loops for increment equal to one. */
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/* jack dongarra, linpack, 3/11/78. */
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/* modified 3/93 to return if incx .le. 0. */
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/* modified 12/3/93, array(1) declarations changed to array(*) */
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/* .. Local Scalars .. */
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/* .. */
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/* .. Intrinsic Functions .. */
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/* .. */
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/* Parameter adjustments */
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--sx;
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/* Function Body */
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ret_val = 0.f;
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stemp = 0.f;
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if (*n <= 0 || *incx <= 0) {
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return ret_val;
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}
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if (*incx == 1) {
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goto L20;
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}
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/* code for increment not equal to 1 */
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nincx = *n * *incx;
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i__1 = nincx;
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i__2 = *incx;
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for (i__ = 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) {
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stemp += (r__1 = sx[i__], dabs(r__1));
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/* L10: */
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}
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ret_val = stemp;
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return ret_val;
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/* code for increment equal to 1 */
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/* clean-up loop */
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L20:
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m = *n % 6;
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if (m == 0) {
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goto L40;
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}
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i__2 = m;
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for (i__ = 1; i__ <= i__2; ++i__) {
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stemp += (r__1 = sx[i__], dabs(r__1));
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/* L30: */
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}
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if (*n < 6) {
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goto L60;
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}
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L40:
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mp1 = m + 1;
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i__2 = *n;
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for (i__ = mp1; i__ <= i__2; i__ += 6) {
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stemp = stemp + (r__1 = sx[i__], dabs(r__1)) + (r__2 = sx[i__ + 1],
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dabs(r__2)) + (r__3 = sx[i__ + 2], dabs(r__3)) + (r__4 = sx[
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i__ + 3], dabs(r__4)) + (r__5 = sx[i__ + 4], dabs(r__5)) + (
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r__6 = sx[i__ + 5], dabs(r__6));
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/* L50: */
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}
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L60:
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ret_val = stemp;
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return ret_val;
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} /* sasum_ */
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