/* Subroutine */
int slasq3_(integer *i0, integer *n0, real *z__, integer *pp, real *dmin__, real *sigma, real *desig, real *qmax, integer *nfail, integer *iter, integer *ndiv, logical *ieee, integer *ttype, real * dmin1, real *dmin2, real *dn, real *dn1, real *dn2, real *g, real * tau)
{
/* System generated locals */
integer i__1;
real r__1, r__2;
/* Builtin functions */
double sqrt(doublereal);
/* Local variables */
real s, t;
integer j4, nn;
real eps, tol;
integer n0in, ipn4;
real tol2, temp;
extern /* Subroutine */
int slasq4_(integer *, integer *, real *, integer *, integer *, real *, real *, real *, real *, real *, real *, real *, integer *, real *), slasq5_(integer *, integer *, real *, integer *, real *, real *, real *, real *, real *, real *, real *, real *, logical *, real *), slasq6_(integer *, integer *, real *, integer *, real *, real *, real *, real *, real *, real *);
extern real slamch_(char *);
extern logical sisnan_(real *);
/* -- LAPACK computational routine (version 3.4.2) -- */
/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
/* September 2012 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. External Function .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Parameter adjustments */
--z__;
/* Function Body */
n0in = *n0;
eps = slamch_("Precision");
tol = eps * 100.f;
/* Computing 2nd power */
r__1 = tol;
tol2 = r__1 * r__1;
/* Check for deflation. */
L10:
if (*n0 < *i0)
{
return 0;
}
if (*n0 == *i0)
{
goto L20;
}
nn = (*n0 << 2) + *pp;
if (*n0 == *i0 + 1)
{
goto L40;
}
/* Check whether E(N0-1) is negligible, 1 eigenvalue. */
if (z__[nn - 5] > tol2 * (*sigma + z__[nn - 3]) && z__[nn - (*pp << 1) - 4] > tol2 * z__[nn - 7])
{
goto L30;
}
L20:
z__[(*n0 << 2) - 3] = z__[(*n0 << 2) + *pp - 3] + *sigma;
--(*n0);
goto L10;
/* Check whether E(N0-2) is negligible, 2 eigenvalues. */
L30:
if (z__[nn - 9] > tol2 * *sigma && z__[nn - (*pp << 1) - 8] > tol2 * z__[ nn - 11])
{
goto L50;
}
L40:
if (z__[nn - 3] > z__[nn - 7])
{
s = z__[nn - 3];
z__[nn - 3] = z__[nn - 7];
z__[nn - 7] = s;
}
t = (z__[nn - 7] - z__[nn - 3] + z__[nn - 5]) * .5f;
if (z__[nn - 5] > z__[nn - 3] * tol2 && t != 0.f)
{
s = z__[nn - 3] * (z__[nn - 5] / t);
if (s <= t)
{
s = z__[nn - 3] * (z__[nn - 5] / (t * (sqrt(s / t + 1.f) + 1.f)));
}
else
{
s = z__[nn - 3] * (z__[nn - 5] / (t + sqrt(t) * sqrt(t + s)));
}
t = z__[nn - 7] + (s + z__[nn - 5]);
z__[nn - 3] *= z__[nn - 7] / t;
z__[nn - 7] = t;
}
z__[(*n0 << 2) - 7] = z__[nn - 7] + *sigma;
z__[(*n0 << 2) - 3] = z__[nn - 3] + *sigma;
*n0 += -2;
goto L10;
L50:
if (*pp == 2)
{
*pp = 0;
}
/* Reverse the qd-array, if warranted. */
if (*dmin__ <= 0.f || *n0 < n0in)
{
if (z__[(*i0 << 2) + *pp - 3] * 1.5f < z__[(*n0 << 2) + *pp - 3])
{
ipn4 = *i0 + *n0 << 2;
i__1 = *i0 + *n0 - 1 << 1;
for (j4 = *i0 << 2;
j4 <= i__1;
j4 += 4)
{
temp = z__[j4 - 3];
z__[j4 - 3] = z__[ipn4 - j4 - 3];
z__[ipn4 - j4 - 3] = temp;
temp = z__[j4 - 2];
z__[j4 - 2] = z__[ipn4 - j4 - 2];
z__[ipn4 - j4 - 2] = temp;
temp = z__[j4 - 1];
z__[j4 - 1] = z__[ipn4 - j4 - 5];
z__[ipn4 - j4 - 5] = temp;
temp = z__[j4];
z__[j4] = z__[ipn4 - j4 - 4];
z__[ipn4 - j4 - 4] = temp;
/* L60: */
}
if (*n0 - *i0 <= 4)
{
z__[(*n0 << 2) + *pp - 1] = z__[(*i0 << 2) + *pp - 1];
z__[(*n0 << 2) - *pp] = z__[(*i0 << 2) - *pp];
}
/* Computing MIN */
r__1 = *dmin2;
r__2 = z__[(*n0 << 2) + *pp - 1]; // , expr subst
*dmin2 = min(r__1,r__2);
/* Computing MIN */
r__1 = z__[(*n0 << 2) + *pp - 1], r__2 = z__[(*i0 << 2) + *pp - 1] ;
r__1 = min(r__1,r__2);
r__2 = z__[(*i0 << 2) + *pp + 3]; // ; expr subst
z__[(*n0 << 2) + *pp - 1] = min(r__1,r__2);
/* Computing MIN */
r__1 = z__[(*n0 << 2) - *pp], r__2 = z__[(*i0 << 2) - *pp];
r__1 = min(r__1,r__2);
r__2 = z__[(*i0 << 2) - *pp + 4]; // ; expr subst
z__[(*n0 << 2) - *pp] = min(r__1,r__2);
/* Computing MAX */
r__1 = *qmax, r__2 = z__[(*i0 << 2) + *pp - 3];
r__1 = max(r__1, r__2);
r__2 = z__[(*i0 << 2) + *pp + 1]; // ; expr subst
*qmax = max(r__1,r__2);
*dmin__ = -0.f;
}
}
/* Choose a shift. */
slasq4_(i0, n0, &z__[1], pp, &n0in, dmin__, dmin1, dmin2, dn, dn1, dn2, tau, ttype, g);
/* Call dqds until DMIN > 0. */
L70:
slasq5_(i0, n0, &z__[1], pp, tau, sigma, dmin__, dmin1, dmin2, dn, dn1, dn2, ieee, &eps);
*ndiv += *n0 - *i0 + 2;
++(*iter);
/* Check status. */
if (*dmin__ >= 0.f && *dmin1 >= 0.f)
{
/* Success. */
goto L90;
}
else if (*dmin__ < 0.f && *dmin1 > 0.f && z__[(*n0 - 1 << 2) - *pp] < tol * (*sigma + *dn1) && abs(*dn) < tol * *sigma)
{
/* Convergence hidden by negative DN. */
z__[(*n0 - 1 << 2) - *pp + 2] = 0.f;
*dmin__ = 0.f;
goto L90;
}
else if (*dmin__ < 0.f)
{
/* TAU too big. Select new TAU and try again. */
++(*nfail);
if (*ttype < -22)
{
/* Failed twice. Play it safe. */
*tau = 0.f;
}
else if (*dmin1 > 0.f)
{
/* Late failure. Gives excellent shift. */
*tau = (*tau + *dmin__) * (1.f - eps * 2.f);
*ttype += -11;
}
else
{
/* Early failure. Divide by 4. */
*tau *= .25f;
*ttype += -12;
}
goto L70;
}
else if (sisnan_(dmin__))
{
/* NaN. */
if (*tau == 0.f)
{
goto L80;
}
else
{
*tau = 0.f;
goto L70;
}
}
else
{
/* Possible underflow. Play it safe. */
goto L80;
}
/* Risk of underflow. */
L80:
slasq6_(i0, n0, &z__[1], pp, dmin__, dmin1, dmin2, dn, dn1, dn2);
*ndiv += *n0 - *i0 + 2;
++(*iter);
*tau = 0.f;
L90:
if (*tau < *sigma)
{
*desig += *tau;
t = *sigma + *desig;
*desig -= t - *sigma;
}
else
{
t = *sigma + *tau;
*desig = *sigma - (t - *tau) + *desig;
}
*sigma = t;
return 0;
/* End of SLASQ3 */
}
/* Subroutine */ int slasq3_(integer *i0, integer *n0, real *z__, integer *pp,
real *dmin__, real *sigma, real *desig, real *qmax, integer *nfail,
integer *iter, integer *ndiv, logical *ieee)
{
/* -- LAPACK auxiliary routine (version 3.0) --
Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
Courant Institute, Argonne National Lab, and Rice University
May 17, 2000
Purpose
=======
SLASQ3 checks for deflation, computes a shift (TAU) and calls dqds.
In case of failure it changes shifts, and tries again until output
is positive.
Arguments
=========
I0 (input) INTEGER
First index.
N0 (input) INTEGER
Last index.
Z (input) REAL array, dimension ( 4*N )
Z holds the qd array.
PP (input) INTEGER
PP=0 for ping, PP=1 for pong.
DMIN (output) REAL
Minimum value of d.
SIGMA (output) REAL
Sum of shifts used in current segment.
DESIG (input/output) REAL
Lower order part of SIGMA
QMAX (input) REAL
Maximum value of q.
NFAIL (output) INTEGER
Number of times shift was too big.
ITER (output) INTEGER
Number of iterations.
NDIV (output) INTEGER
Number of divisions.
TTYPE (output) INTEGER
Shift type.
IEEE (input) LOGICAL
Flag for IEEE or non IEEE arithmetic (passed to SLASQ5).
=====================================================================
Parameter adjustments */
/* Initialized data */
static integer ttype = 0;
static real dmin1 = 0.f;
static real dmin2 = 0.f;
static real dn = 0.f;
static real dn1 = 0.f;
static real dn2 = 0.f;
static real tau = 0.f;
/* System generated locals */
integer i__1;
real r__1, r__2;
/* Builtin functions */
double sqrt(doublereal);
/* Local variables */
static real temp, s, t;
static integer j4;
extern /* Subroutine */ int slasq4_(integer *, integer *, real *, integer
*, integer *, real *, real *, real *, real *, real *, real *,
real *, integer *), slasq5_(integer *, integer *, real *, integer
*, real *, real *, real *, real *, real *, real *, real *,
logical *), slasq6_(integer *, integer *, real *, integer *, real
*, real *, real *, real *, real *, real *);
static integer nn;
extern doublereal slamch_(char *);
static real safmin, eps, tol;
static integer n0in, ipn4;
static real tol2;
--z__;
/* Function Body */
n0in = *n0;
eps = slamch_("Precision");
safmin = slamch_("Safe minimum");
tol = eps * 100.f;
/* Computing 2nd power */
r__1 = tol;
tol2 = r__1 * r__1;
/* Check for deflation. */
L10:
if (*n0 < *i0) {
return 0;
}
if (*n0 == *i0) {
goto L20;
}
nn = (*n0 << 2) + *pp;
if (*n0 == *i0 + 1) {
goto L40;
}
/* Check whether E(N0-1) is negligible, 1 eigenvalue. */
if (z__[nn - 5] > tol2 * (*sigma + z__[nn - 3]) && z__[nn - (*pp << 1) -
4] > tol2 * z__[nn - 7]) {
goto L30;
}
L20:
z__[(*n0 << 2) - 3] = z__[(*n0 << 2) + *pp - 3] + *sigma;
--(*n0);
goto L10;
/* Check whether E(N0-2) is negligible, 2 eigenvalues. */
L30:
if (z__[nn - 9] > tol2 * *sigma && z__[nn - (*pp << 1) - 8] > tol2 * z__[
nn - 11]) {
goto L50;
}
L40:
if (z__[nn - 3] > z__[nn - 7]) {
s = z__[nn - 3];
z__[nn - 3] = z__[nn - 7];
z__[nn - 7] = s;
}
if (z__[nn - 5] > z__[nn - 3] * tol2) {
t = (z__[nn - 7] - z__[nn - 3] + z__[nn - 5]) * .5f;
s = z__[nn - 3] * (z__[nn - 5] / t);
if (s <= t) {
s = z__[nn - 3] * (z__[nn - 5] / (t * (sqrt(s / t + 1.f) + 1.f)));
} else {
s = z__[nn - 3] * (z__[nn - 5] / (t + sqrt(t) * sqrt(t + s)));
}
t = z__[nn - 7] + (s + z__[nn - 5]);
z__[nn - 3] *= z__[nn - 7] / t;
z__[nn - 7] = t;
}
z__[(*n0 << 2) - 7] = z__[nn - 7] + *sigma;
z__[(*n0 << 2) - 3] = z__[nn - 3] + *sigma;
*n0 += -2;
goto L10;
L50:
/* Reverse the qd-array, if warranted. */
if (*dmin__ <= 0.f || *n0 < n0in) {
if (z__[(*i0 << 2) + *pp - 3] * 1.5f < z__[(*n0 << 2) + *pp - 3]) {
ipn4 = *i0 + *n0 << 2;
i__1 = *i0 + *n0 - 1 << 1;
for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
temp = z__[j4 - 3];
z__[j4 - 3] = z__[ipn4 - j4 - 3];
z__[ipn4 - j4 - 3] = temp;
temp = z__[j4 - 2];
z__[j4 - 2] = z__[ipn4 - j4 - 2];
z__[ipn4 - j4 - 2] = temp;
temp = z__[j4 - 1];
z__[j4 - 1] = z__[ipn4 - j4 - 5];
z__[ipn4 - j4 - 5] = temp;
temp = z__[j4];
z__[j4] = z__[ipn4 - j4 - 4];
z__[ipn4 - j4 - 4] = temp;
/* L60: */
}
if (*n0 - *i0 <= 4) {
z__[(*n0 << 2) + *pp - 1] = z__[(*i0 << 2) + *pp - 1];
z__[(*n0 << 2) - *pp] = z__[(*i0 << 2) - *pp];
}
/* Computing MIN */
r__1 = dmin2, r__2 = z__[(*n0 << 2) + *pp - 1];
dmin2 = dmin(r__1,r__2);
/* Computing MIN */
r__1 = z__[(*n0 << 2) + *pp - 1], r__2 = z__[(*i0 << 2) + *pp - 1]
, r__1 = min(r__1,r__2), r__2 = z__[(*i0 << 2) + *pp + 3];
z__[(*n0 << 2) + *pp - 1] = dmin(r__1,r__2);
/* Computing MIN */
r__1 = z__[(*n0 << 2) - *pp], r__2 = z__[(*i0 << 2) - *pp], r__1 =
min(r__1,r__2), r__2 = z__[(*i0 << 2) - *pp + 4];
z__[(*n0 << 2) - *pp] = dmin(r__1,r__2);
/* Computing MAX */
r__1 = *qmax, r__2 = z__[(*i0 << 2) + *pp - 3], r__1 = max(r__1,
r__2), r__2 = z__[(*i0 << 2) + *pp + 1];
*qmax = dmax(r__1,r__2);
*dmin__ = 0.f;
}
}
/* L70:
Computing MIN */
r__1 = z__[(*n0 << 2) + *pp - 1], r__2 = z__[(*n0 << 2) + *pp - 9], r__1 =
min(r__1,r__2), r__2 = dmin2 + z__[(*n0 << 2) - *pp];
if (*dmin__ < 0.f || safmin * *qmax < dmin(r__1,r__2)) {
/* Choose a shift. */
slasq4_(i0, n0, &z__[1], pp, &n0in, dmin__, &dmin1, &dmin2, &dn, &dn1,
&dn2, &tau, &ttype);
/* Call dqds until DMIN > 0. */
L80:
slasq5_(i0, n0, &z__[1], pp, &tau, dmin__, &dmin1, &dmin2, &dn, &dn1,
&dn2, ieee);
*ndiv += *n0 - *i0 + 2;
++(*iter);
/* Check status. */
if (*dmin__ >= 0.f && dmin1 > 0.f) {
/* Success. */
goto L100;
} else if (*dmin__ < 0.f && dmin1 > 0.f && z__[(*n0 - 1 << 2) - *pp] <
tol * (*sigma + dn1) && dabs(dn) < tol * *sigma) {
/* Convergence hidden by negative DN. */
z__[(*n0 - 1 << 2) - *pp + 2] = 0.f;
*dmin__ = 0.f;
goto L100;
} else if (*dmin__ < 0.f) {
/* TAU too big. Select new TAU and try again. */
++(*nfail);
if (ttype < -22) {
/* Failed twice. Play it safe. */
tau = 0.f;
} else if (dmin1 > 0.f) {
/* Late failure. Gives excellent shift. */
tau = (tau + *dmin__) * (1.f - eps * 2.f);
ttype += -11;
} else {
/* Early failure. Divide by 4. */
tau *= .25f;
ttype += -12;
}
goto L80;
} else if (*dmin__ != *dmin__) {
/* NaN. */
tau = 0.f;
goto L80;
} else {
/* Possible underflow. Play it safe. */
goto L90;
}
}
/* Risk of underflow. */
L90:
slasq6_(i0, n0, &z__[1], pp, dmin__, &dmin1, &dmin2, &dn, &dn1, &dn2);
*ndiv += *n0 - *i0 + 2;
++(*iter);
tau = 0.f;
L100:
if (tau < *sigma) {
*desig += tau;
t = *sigma + *desig;
*desig -= t - *sigma;
} else {
t = *sigma + tau;
*desig = *sigma - (t - tau) + *desig;
}
*sigma = t;
return 0;
/* End of SLASQ3 */
} /* slasq3_ */
/* Subroutine */ int slasq3_(integer *i0, integer *n0, real *z__, integer *pp,
real *dmin__, real *sigma, real *desig, real *qmax, integer *nfail,
integer *iter, integer *ndiv, logical *ieee, integer *ttype, real *
dmin1, real *dmin2, real *dn, real *dn1, real *dn2, real *g, real *
tau)
{
/* System generated locals */
integer i__1;
real r__1, r__2;
/* Builtin functions */
double sqrt(doublereal);
/* Local variables */
real s, t;
integer j4, nn;
real eps, tol;
integer n0in, ipn4;
real tol2, temp;
extern /* Subroutine */ int slasq4_(integer *, integer *, real *, integer
*, integer *, real *, real *, real *, real *, real *, real *,
real *, integer *, real *), slasq5_(integer *, integer *, real *,
integer *, real *, real *, real *, real *, real *, real *, real *,
logical *), slasq6_(integer *, integer *, real *, integer *,
real *, real *, real *, real *, real *, real *);
extern doublereal slamch_(char *);
extern logical sisnan_(real *);
/* -- LAPACK routine (version 3.2) -- */
/* -- Contributed by Osni Marques of the Lawrence Berkeley National -- */
/* -- Laboratory and Beresford Parlett of the Univ. of California at -- */
/* -- Berkeley -- */
/* -- November 2008 -- */
/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* SLASQ3 checks for deflation, computes a shift (TAU) and calls dqds. */
/* In case of failure it changes shifts, and tries again until output */
/* is positive. */
/* Arguments */
/* ========= */
/* I0 (input) INTEGER */
/* First index. */
/* N0 (input) INTEGER */
/* Last index. */
/* Z (input) REAL array, dimension ( 4*N ) */
/* Z holds the qd array. */
/* PP (input/output) INTEGER */
/* PP=0 for ping, PP=1 for pong. */
/* PP=2 indicates that flipping was applied to the Z array */
/* and that the initial tests for deflation should not be */
/* performed. */
/* DMIN (output) REAL */
/* Minimum value of d. */
/* SIGMA (output) REAL */
/* Sum of shifts used in current segment. */
/* DESIG (input/output) REAL */
/* Lower order part of SIGMA */
/* QMAX (input) REAL */
/* Maximum value of q. */
/* NFAIL (output) INTEGER */
/* Number of times shift was too big. */
/* ITER (output) INTEGER */
/* Number of iterations. */
/* NDIV (output) INTEGER */
/* Number of divisions. */
/* IEEE (input) LOGICAL */
/* Flag for IEEE or non IEEE arithmetic (passed to SLASQ5). */
/* TTYPE (input/output) INTEGER */
/* Shift type. */
/* DMIN1, DMIN2, DN, DN1, DN2, G, TAU (input/output) REAL */
/* These are passed as arguments in order to save their values */
/* between calls to SLASQ3. */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. External Function .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Parameter adjustments */
--z__;
/* Function Body */
n0in = *n0;
eps = slamch_("Precision");
tol = eps * 100.f;
/* Computing 2nd power */
r__1 = tol;
tol2 = r__1 * r__1;
/* Check for deflation. */
L10:
if (*n0 < *i0) {
return 0;
}
if (*n0 == *i0) {
goto L20;
}
nn = (*n0 << 2) + *pp;
if (*n0 == *i0 + 1) {
goto L40;
}
/* Check whether E(N0-1) is negligible, 1 eigenvalue. */
if (z__[nn - 5] > tol2 * (*sigma + z__[nn - 3]) && z__[nn - (*pp << 1) -
4] > tol2 * z__[nn - 7]) {
goto L30;
}
L20:
z__[(*n0 << 2) - 3] = z__[(*n0 << 2) + *pp - 3] + *sigma;
--(*n0);
goto L10;
/* Check whether E(N0-2) is negligible, 2 eigenvalues. */
L30:
if (z__[nn - 9] > tol2 * *sigma && z__[nn - (*pp << 1) - 8] > tol2 * z__[
nn - 11]) {
goto L50;
}
L40:
if (z__[nn - 3] > z__[nn - 7]) {
s = z__[nn - 3];
z__[nn - 3] = z__[nn - 7];
z__[nn - 7] = s;
}
if (z__[nn - 5] > z__[nn - 3] * tol2) {
t = (z__[nn - 7] - z__[nn - 3] + z__[nn - 5]) * .5f;
s = z__[nn - 3] * (z__[nn - 5] / t);
if (s <= t) {
s = z__[nn - 3] * (z__[nn - 5] / (t * (sqrt(s / t + 1.f) + 1.f)));
} else {
s = z__[nn - 3] * (z__[nn - 5] / (t + sqrt(t) * sqrt(t + s)));
}
t = z__[nn - 7] + (s + z__[nn - 5]);
z__[nn - 3] *= z__[nn - 7] / t;
z__[nn - 7] = t;
}
z__[(*n0 << 2) - 7] = z__[nn - 7] + *sigma;
z__[(*n0 << 2) - 3] = z__[nn - 3] + *sigma;
*n0 += -2;
goto L10;
L50:
if (*pp == 2) {
*pp = 0;
}
/* Reverse the qd-array, if warranted. */
if (*dmin__ <= 0.f || *n0 < n0in) {
if (z__[(*i0 << 2) + *pp - 3] * 1.5f < z__[(*n0 << 2) + *pp - 3]) {
ipn4 = *i0 + *n0 << 2;
i__1 = *i0 + *n0 - 1 << 1;
for (j4 = *i0 << 2; j4 <= i__1; j4 += 4) {
temp = z__[j4 - 3];
z__[j4 - 3] = z__[ipn4 - j4 - 3];
z__[ipn4 - j4 - 3] = temp;
temp = z__[j4 - 2];
z__[j4 - 2] = z__[ipn4 - j4 - 2];
z__[ipn4 - j4 - 2] = temp;
temp = z__[j4 - 1];
z__[j4 - 1] = z__[ipn4 - j4 - 5];
z__[ipn4 - j4 - 5] = temp;
temp = z__[j4];
z__[j4] = z__[ipn4 - j4 - 4];
z__[ipn4 - j4 - 4] = temp;
/* L60: */
}
if (*n0 - *i0 <= 4) {
z__[(*n0 << 2) + *pp - 1] = z__[(*i0 << 2) + *pp - 1];
z__[(*n0 << 2) - *pp] = z__[(*i0 << 2) - *pp];
}
/* Computing MIN */
r__1 = *dmin2, r__2 = z__[(*n0 << 2) + *pp - 1];
*dmin2 = dmin(r__1,r__2);
/* Computing MIN */
r__1 = z__[(*n0 << 2) + *pp - 1], r__2 = z__[(*i0 << 2) + *pp - 1]
, r__1 = min(r__1,r__2), r__2 = z__[(*i0 << 2) + *pp + 3];
z__[(*n0 << 2) + *pp - 1] = dmin(r__1,r__2);
/* Computing MIN */
r__1 = z__[(*n0 << 2) - *pp], r__2 = z__[(*i0 << 2) - *pp], r__1 =
min(r__1,r__2), r__2 = z__[(*i0 << 2) - *pp + 4];
z__[(*n0 << 2) - *pp] = dmin(r__1,r__2);
/* Computing MAX */
r__1 = *qmax, r__2 = z__[(*i0 << 2) + *pp - 3], r__1 = max(r__1,
r__2), r__2 = z__[(*i0 << 2) + *pp + 1];
*qmax = dmax(r__1,r__2);
*dmin__ = -0.f;
}
}
/* Choose a shift. */
slasq4_(i0, n0, &z__[1], pp, &n0in, dmin__, dmin1, dmin2, dn, dn1, dn2,
tau, ttype, g);
/* Call dqds until DMIN > 0. */
L70:
slasq5_(i0, n0, &z__[1], pp, tau, dmin__, dmin1, dmin2, dn, dn1, dn2,
ieee);
*ndiv += *n0 - *i0 + 2;
++(*iter);
/* Check status. */
if (*dmin__ >= 0.f && *dmin1 > 0.f) {
/* Success. */
goto L90;
} else if (*dmin__ < 0.f && *dmin1 > 0.f && z__[(*n0 - 1 << 2) - *pp] <
tol * (*sigma + *dn1) && dabs(*dn) < tol * *sigma) {
/* Convergence hidden by negative DN. */
z__[(*n0 - 1 << 2) - *pp + 2] = 0.f;
*dmin__ = 0.f;
goto L90;
} else if (*dmin__ < 0.f) {
/* TAU too big. Select new TAU and try again. */
++(*nfail);
if (*ttype < -22) {
/* Failed twice. Play it safe. */
*tau = 0.f;
} else if (*dmin1 > 0.f) {
/* Late failure. Gives excellent shift. */
*tau = (*tau + *dmin__) * (1.f - eps * 2.f);
*ttype += -11;
} else {
/* Early failure. Divide by 4. */
*tau *= .25f;
*ttype += -12;
}
goto L70;
} else if (sisnan_(dmin__)) {
/* NaN. */
if (*tau == 0.f) {
goto L80;
} else {
*tau = 0.f;
goto L70;
}
} else {
/* Possible underflow. Play it safe. */
goto L80;
}
/* Risk of underflow. */
L80:
slasq6_(i0, n0, &z__[1], pp, dmin__, dmin1, dmin2, dn, dn1, dn2);
*ndiv += *n0 - *i0 + 2;
++(*iter);
*tau = 0.f;
L90:
if (*tau < *sigma) {
*desig += *tau;
t = *sigma + *desig;
*desig -= t - *sigma;
} else {
t = *sigma + *tau;
*desig = *sigma - (t - *tau) + *desig;
}
*sigma = t;
return 0;
/* End of SLASQ3 */
} /* slasq3_ */