240 lines
8.7 KiB
C++
240 lines
8.7 KiB
C++
#ifdef __cplusplus
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extern "C" {
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#endif
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#include "lmp_f2c.h"
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int dlasq5_(integer *i0, integer *n0, doublereal *z__, integer *pp, doublereal *tau,
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doublereal *sigma, doublereal *dmin__, doublereal *dmin1, doublereal *dmin2,
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doublereal *dn, doublereal *dnm1, doublereal *dnm2, logical *ieee, doublereal *eps)
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{
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integer i__1;
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doublereal d__1, d__2;
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doublereal d__;
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integer j4, j4p2;
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doublereal emin, temp, dthresh;
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--z__;
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if (*n0 - *i0 - 1 <= 0) {
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return 0;
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}
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dthresh = *eps * (*sigma + *tau);
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if (*tau < dthresh * .5) {
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*tau = 0.;
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}
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if (*tau != 0.) {
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j4 = (*i0 << 2) + *pp - 3;
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emin = z__[j4 + 4];
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d__ = z__[j4] - *tau;
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*dmin__ = d__;
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*dmin1 = -z__[j4];
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if (*ieee) {
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if (*pp == 0) {
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i__1 = *n0 - 3 << 2;
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for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
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z__[j4 - 2] = d__ + z__[j4 - 1];
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temp = z__[j4 + 1] / z__[j4 - 2];
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d__ = d__ * temp - *tau;
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*dmin__ = min(*dmin__, d__);
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z__[j4] = z__[j4 - 1] * temp;
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d__1 = z__[j4];
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emin = min(d__1, emin);
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}
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} else {
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i__1 = *n0 - 3 << 2;
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for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
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z__[j4 - 3] = d__ + z__[j4];
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temp = z__[j4 + 2] / z__[j4 - 3];
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d__ = d__ * temp - *tau;
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*dmin__ = min(*dmin__, d__);
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z__[j4 - 1] = z__[j4] * temp;
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d__1 = z__[j4 - 1];
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emin = min(d__1, emin);
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}
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}
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*dnm2 = d__;
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*dmin2 = *dmin__;
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j4 = (*n0 - 2 << 2) - *pp;
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j4p2 = j4 + (*pp << 1) - 1;
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z__[j4 - 2] = *dnm2 + z__[j4p2];
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z__[j4] = z__[j4p2 + 2] * (z__[j4p2] / z__[j4 - 2]);
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*dnm1 = z__[j4p2 + 2] * (*dnm2 / z__[j4 - 2]) - *tau;
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*dmin__ = min(*dmin__, *dnm1);
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*dmin1 = *dmin__;
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j4 += 4;
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j4p2 = j4 + (*pp << 1) - 1;
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z__[j4 - 2] = *dnm1 + z__[j4p2];
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z__[j4] = z__[j4p2 + 2] * (z__[j4p2] / z__[j4 - 2]);
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*dn = z__[j4p2 + 2] * (*dnm1 / z__[j4 - 2]) - *tau;
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*dmin__ = min(*dmin__, *dn);
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} else {
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if (*pp == 0) {
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i__1 = *n0 - 3 << 2;
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for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
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z__[j4 - 2] = d__ + z__[j4 - 1];
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if (d__ < 0.) {
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return 0;
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} else {
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z__[j4] = z__[j4 + 1] * (z__[j4 - 1] / z__[j4 - 2]);
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d__ = z__[j4 + 1] * (d__ / z__[j4 - 2]) - *tau;
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}
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*dmin__ = min(*dmin__, d__);
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d__1 = emin, d__2 = z__[j4];
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emin = min(d__1, d__2);
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}
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} else {
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i__1 = *n0 - 3 << 2;
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for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
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z__[j4 - 3] = d__ + z__[j4];
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if (d__ < 0.) {
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return 0;
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} else {
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z__[j4 - 1] = z__[j4 + 2] * (z__[j4] / z__[j4 - 3]);
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d__ = z__[j4 + 2] * (d__ / z__[j4 - 3]) - *tau;
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}
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*dmin__ = min(*dmin__, d__);
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d__1 = emin, d__2 = z__[j4 - 1];
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emin = min(d__1, d__2);
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}
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}
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*dnm2 = d__;
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*dmin2 = *dmin__;
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j4 = (*n0 - 2 << 2) - *pp;
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j4p2 = j4 + (*pp << 1) - 1;
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z__[j4 - 2] = *dnm2 + z__[j4p2];
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if (*dnm2 < 0.) {
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return 0;
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} else {
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z__[j4] = z__[j4p2 + 2] * (z__[j4p2] / z__[j4 - 2]);
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*dnm1 = z__[j4p2 + 2] * (*dnm2 / z__[j4 - 2]) - *tau;
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}
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*dmin__ = min(*dmin__, *dnm1);
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*dmin1 = *dmin__;
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j4 += 4;
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j4p2 = j4 + (*pp << 1) - 1;
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z__[j4 - 2] = *dnm1 + z__[j4p2];
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if (*dnm1 < 0.) {
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return 0;
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} else {
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z__[j4] = z__[j4p2 + 2] * (z__[j4p2] / z__[j4 - 2]);
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*dn = z__[j4p2 + 2] * (*dnm1 / z__[j4 - 2]) - *tau;
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}
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*dmin__ = min(*dmin__, *dn);
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}
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} else {
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j4 = (*i0 << 2) + *pp - 3;
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emin = z__[j4 + 4];
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d__ = z__[j4] - *tau;
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*dmin__ = d__;
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*dmin1 = -z__[j4];
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if (*ieee) {
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if (*pp == 0) {
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i__1 = *n0 - 3 << 2;
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for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
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z__[j4 - 2] = d__ + z__[j4 - 1];
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temp = z__[j4 + 1] / z__[j4 - 2];
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d__ = d__ * temp - *tau;
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if (d__ < dthresh) {
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d__ = 0.;
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}
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*dmin__ = min(*dmin__, d__);
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z__[j4] = z__[j4 - 1] * temp;
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d__1 = z__[j4];
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emin = min(d__1, emin);
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}
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} else {
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i__1 = *n0 - 3 << 2;
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for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
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z__[j4 - 3] = d__ + z__[j4];
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temp = z__[j4 + 2] / z__[j4 - 3];
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d__ = d__ * temp - *tau;
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if (d__ < dthresh) {
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d__ = 0.;
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}
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*dmin__ = min(*dmin__, d__);
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z__[j4 - 1] = z__[j4] * temp;
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d__1 = z__[j4 - 1];
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emin = min(d__1, emin);
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}
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}
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*dnm2 = d__;
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*dmin2 = *dmin__;
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j4 = (*n0 - 2 << 2) - *pp;
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j4p2 = j4 + (*pp << 1) - 1;
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z__[j4 - 2] = *dnm2 + z__[j4p2];
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z__[j4] = z__[j4p2 + 2] * (z__[j4p2] / z__[j4 - 2]);
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*dnm1 = z__[j4p2 + 2] * (*dnm2 / z__[j4 - 2]) - *tau;
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*dmin__ = min(*dmin__, *dnm1);
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*dmin1 = *dmin__;
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j4 += 4;
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j4p2 = j4 + (*pp << 1) - 1;
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z__[j4 - 2] = *dnm1 + z__[j4p2];
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z__[j4] = z__[j4p2 + 2] * (z__[j4p2] / z__[j4 - 2]);
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*dn = z__[j4p2 + 2] * (*dnm1 / z__[j4 - 2]) - *tau;
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*dmin__ = min(*dmin__, *dn);
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} else {
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if (*pp == 0) {
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i__1 = *n0 - 3 << 2;
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for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
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z__[j4 - 2] = d__ + z__[j4 - 1];
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if (d__ < 0.) {
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return 0;
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} else {
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z__[j4] = z__[j4 + 1] * (z__[j4 - 1] / z__[j4 - 2]);
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d__ = z__[j4 + 1] * (d__ / z__[j4 - 2]) - *tau;
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}
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if (d__ < dthresh) {
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d__ = 0.;
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}
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*dmin__ = min(*dmin__, d__);
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d__1 = emin, d__2 = z__[j4];
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emin = min(d__1, d__2);
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}
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} else {
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i__1 = *n0 - 3 << 2;
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for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
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z__[j4 - 3] = d__ + z__[j4];
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if (d__ < 0.) {
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return 0;
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} else {
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z__[j4 - 1] = z__[j4 + 2] * (z__[j4] / z__[j4 - 3]);
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d__ = z__[j4 + 2] * (d__ / z__[j4 - 3]) - *tau;
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}
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if (d__ < dthresh) {
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d__ = 0.;
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}
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*dmin__ = min(*dmin__, d__);
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d__1 = emin, d__2 = z__[j4 - 1];
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emin = min(d__1, d__2);
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}
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}
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*dnm2 = d__;
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*dmin2 = *dmin__;
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j4 = (*n0 - 2 << 2) - *pp;
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j4p2 = j4 + (*pp << 1) - 1;
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z__[j4 - 2] = *dnm2 + z__[j4p2];
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if (*dnm2 < 0.) {
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return 0;
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} else {
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z__[j4] = z__[j4p2 + 2] * (z__[j4p2] / z__[j4 - 2]);
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*dnm1 = z__[j4p2 + 2] * (*dnm2 / z__[j4 - 2]) - *tau;
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}
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*dmin__ = min(*dmin__, *dnm1);
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*dmin1 = *dmin__;
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j4 += 4;
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j4p2 = j4 + (*pp << 1) - 1;
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z__[j4 - 2] = *dnm1 + z__[j4p2];
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if (*dnm1 < 0.) {
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return 0;
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} else {
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z__[j4] = z__[j4p2 + 2] * (z__[j4p2] / z__[j4 - 2]);
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*dn = z__[j4p2 + 2] * (*dnm1 / z__[j4 - 2]) - *tau;
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}
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*dmin__ = min(*dmin__, *dn);
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}
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}
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z__[j4 + 2] = *dn;
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z__[(*n0 << 2) - *pp] = emin;
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return 0;
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}
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#ifdef __cplusplus
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}
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#endif
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