OpenBLAS/relapack/src/dsytrf_rook_rec2.c

452 lines
12 KiB
C

/* -- translated by f2c (version 20100827).
You must link the resulting object file with libf2c:
on Microsoft Windows system, link with libf2c.lib;
on Linux or Unix systems, link with .../path/to/libf2c.a -lm
or, if you install libf2c.a in a standard place, with -lf2c -lm
-- in that order, at the end of the command line, as in
cc *.o -lf2c -lm
Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
http://www.netlib.org/f2c/libf2c.zip
*/
#include "f2c.h"
/* Table of constant values */
static blasint c__1 = 1;
static double c_b9 = -1.;
static double c_b10 = 1.;
/** DSYTRF_ROOK_REC2 computes a partial factorization of a real symmetric matrix using the bounded Bunch-Kaufma n ("rook") diagonal pivoting method.
*
* This routine is a minor modification of LAPACK's dlasyf.
* It serves as an unblocked kernel in the recursive algorithms.
* The blocked BLAS Level 3 updates were removed and moved to the
* recursive algorithm.
* */
/* Subroutine */ void RELAPACK_dsytrf_rook_rec2(char *uplo, blasint *n,
int *nb, blasint *kb, double *a, blasint *lda, blasint *ipiv,
double *w, blasint *ldw, blasint *info, ftnlen uplo_len)
{
/* System generated locals */
blasint a_dim1, a_offset, w_dim1, w_offset, i__1, i__2;
double d__1;
/* Builtin functions */
double sqrt(double);
/* Local variables */
static blasint j, k, p;
static double t, r1, d11, d12, d21, d22;
static blasint ii, jj, kk, kp, kw, jp1, jp2, kkw;
static logical done;
static blasint imax, jmax;
static double alpha;
extern /* Subroutine */ blasint dscal_(int *, double *, double *,
blasint *);
extern logical lsame_(char *, char *, ftnlen, ftnlen);
extern /* Subroutine */ blasint dgemv_(char *, blasint *, blasint *,
double *, double *, blasint *, double *, blasint *,
double *, double *, blasint *, ftnlen);
static double dtemp, sfmin;
static blasint itemp;
extern /* Subroutine */ blasint dcopy_(int *, double *, blasint *,
double *, blasint *), dswap_(int *, double *, int
*, double *, blasint *);
static blasint kstep;
extern double dlamch_(char *, ftnlen);
static double absakk;
extern blasint idamax_(int *, double *, blasint *);
static double colmax, rowmax;
/* Parameter adjustments */
a_dim1 = *lda;
a_offset = 1 + a_dim1;
a -= a_offset;
--ipiv;
w_dim1 = *ldw;
w_offset = 1 + w_dim1;
w -= w_offset;
/* Function Body */
*info = 0;
alpha = (sqrt(17.) + 1.) / 8.;
sfmin = dlamch_("S", (ftnlen)1);
if (lsame_(uplo, "U", (ftnlen)1, (ftnlen)1)) {
k = *n;
L10:
kw = *nb + k - *n;
if ((k <= *n - *nb + 1 && *nb < *n) || k < 1) {
goto L30;
}
kstep = 1;
p = k;
dcopy_(&k, &a[k * a_dim1 + 1], &c__1, &w[kw * w_dim1 + 1], &c__1);
if (k < *n) {
i__1 = *n - k;
dgemv_("No transpose", &k, &i__1, &c_b9, &a[(k + 1) * a_dim1 + 1],
lda, &w[k + (kw + 1) * w_dim1], ldw, &c_b10, &w[kw *
w_dim1 + 1], &c__1, (ftnlen)12);
}
absakk = (d__1 = w[k + kw * w_dim1], abs(d__1));
if (k > 1) {
i__1 = k - 1;
imax = idamax_(&i__1, &w[kw * w_dim1 + 1], &c__1);
colmax = (d__1 = w[imax + kw * w_dim1], abs(d__1));
} else {
colmax = 0.;
}
if (max(absakk,colmax) == 0.) {
if (*info == 0) {
*info = k;
}
kp = k;
dcopy_(&k, &w[kw * w_dim1 + 1], &c__1, &a[k * a_dim1 + 1], &c__1);
} else {
if (! (absakk < alpha * colmax)) {
kp = k;
} else {
done = FALSE_;
L12:
dcopy_(&imax, &a[imax * a_dim1 + 1], &c__1, &w[(kw - 1) *
w_dim1 + 1], &c__1);
i__1 = k - imax;
dcopy_(&i__1, &a[imax + (imax + 1) * a_dim1], lda, &w[imax +
1 + (kw - 1) * w_dim1], &c__1);
if (k < *n) {
i__1 = *n - k;
dgemv_("No transpose", &k, &i__1, &c_b9, &a[(k + 1) *
a_dim1 + 1], lda, &w[imax + (kw + 1) * w_dim1],
ldw, &c_b10, &w[(kw - 1) * w_dim1 + 1], &c__1, (
ftnlen)12);
}
if (imax != k) {
i__1 = k - imax;
jmax = imax + idamax_(&i__1, &w[imax + 1 + (kw - 1) *
w_dim1], &c__1);
rowmax = (d__1 = w[jmax + (kw - 1) * w_dim1], abs(d__1));
} else {
rowmax = 0.;
}
if (imax > 1) {
i__1 = imax - 1;
itemp = idamax_(&i__1, &w[(kw - 1) * w_dim1 + 1], &c__1);
dtemp = (d__1 = w[itemp + (kw - 1) * w_dim1], abs(d__1));
if (dtemp > rowmax) {
rowmax = dtemp;
jmax = itemp;
}
}
if (! ((d__1 = w[imax + (kw - 1) * w_dim1], abs(d__1)) <
alpha * rowmax)) {
kp = imax;
dcopy_(&k, &w[(kw - 1) * w_dim1 + 1], &c__1, &w[kw *
w_dim1 + 1], &c__1);
done = TRUE_;
} else if (p == jmax || rowmax <= colmax) {
kp = imax;
kstep = 2;
done = TRUE_;
} else {
p = imax;
colmax = rowmax;
imax = jmax;
dcopy_(&k, &w[(kw - 1) * w_dim1 + 1], &c__1, &w[kw *
w_dim1 + 1], &c__1);
}
if (! done) {
goto L12;
}
}
kk = k - kstep + 1;
kkw = *nb + kk - *n;
if (kstep == 2 && p != k) {
i__1 = k - p;
dcopy_(&i__1, &a[p + 1 + k * a_dim1], &c__1, &a[p + (p + 1) *
a_dim1], lda);
dcopy_(&p, &a[k * a_dim1 + 1], &c__1, &a[p * a_dim1 + 1], &
c__1);
i__1 = *n - k + 1;
dswap_(&i__1, &a[k + k * a_dim1], lda, &a[p + k * a_dim1],
lda);
i__1 = *n - kk + 1;
dswap_(&i__1, &w[k + kkw * w_dim1], ldw, &w[p + kkw * w_dim1],
ldw);
}
if (kp != kk) {
a[kp + k * a_dim1] = a[kk + k * a_dim1];
i__1 = k - 1 - kp;
dcopy_(&i__1, &a[kp + 1 + kk * a_dim1], &c__1, &a[kp + (kp +
1) * a_dim1], lda);
dcopy_(&kp, &a[kk * a_dim1 + 1], &c__1, &a[kp * a_dim1 + 1], &
c__1);
i__1 = *n - kk + 1;
dswap_(&i__1, &a[kk + kk * a_dim1], lda, &a[kp + kk * a_dim1],
lda);
i__1 = *n - kk + 1;
dswap_(&i__1, &w[kk + kkw * w_dim1], ldw, &w[kp + kkw *
w_dim1], ldw);
}
if (kstep == 1) {
dcopy_(&k, &w[kw * w_dim1 + 1], &c__1, &a[k * a_dim1 + 1], &
c__1);
if (k > 1) {
if ((d__1 = a[k + k * a_dim1], abs(d__1)) >= sfmin) {
r1 = 1. / a[k + k * a_dim1];
i__1 = k - 1;
dscal_(&i__1, &r1, &a[k * a_dim1 + 1], &c__1);
} else if (a[k + k * a_dim1] != 0.) {
i__1 = k - 1;
for (ii = 1; ii <= i__1; ++ii) {
a[ii + k * a_dim1] /= a[k + k * a_dim1];
/* L14: */
}
}
}
} else {
if (k > 2) {
d12 = w[k - 1 + kw * w_dim1];
d11 = w[k + kw * w_dim1] / d12;
d22 = w[k - 1 + (kw - 1) * w_dim1] / d12;
t = 1. / (d11 * d22 - 1.);
i__1 = k - 2;
for (j = 1; j <= i__1; ++j) {
a[j + (k - 1) * a_dim1] = t * ((d11 * w[j + (kw - 1) *
w_dim1] - w[j + kw * w_dim1]) / d12);
a[j + k * a_dim1] = t * ((d22 * w[j + kw * w_dim1] -
w[j + (kw - 1) * w_dim1]) / d12);
/* L20: */
}
}
a[k - 1 + (k - 1) * a_dim1] = w[k - 1 + (kw - 1) * w_dim1];
a[k - 1 + k * a_dim1] = w[k - 1 + kw * w_dim1];
a[k + k * a_dim1] = w[k + kw * w_dim1];
}
}
if (kstep == 1) {
ipiv[k] = kp;
} else {
ipiv[k] = -p;
ipiv[k - 1] = -kp;
}
k -= kstep;
goto L10;
L30:
j = k + 1;
L60:
kstep = 1;
jp1 = 1;
jj = j;
jp2 = ipiv[j];
if (jp2 < 0) {
jp2 = -jp2;
++j;
jp1 = -ipiv[j];
kstep = 2;
}
++j;
if (jp2 != jj && j <= *n) {
i__1 = *n - j + 1;
dswap_(&i__1, &a[jp2 + j * a_dim1], lda, &a[jj + j * a_dim1], lda)
;
}
jj = j - 1;
if (jp1 != jj && kstep == 2) {
i__1 = *n - j + 1;
dswap_(&i__1, &a[jp1 + j * a_dim1], lda, &a[jj + j * a_dim1], lda)
;
}
if (j <= *n) {
goto L60;
}
*kb = *n - k;
} else {
k = 1;
L70:
if ((k >= *nb && *nb < *n) || k > *n) {
goto L90;
}
kstep = 1;
p = k;
i__1 = *n - k + 1;
dcopy_(&i__1, &a[k + k * a_dim1], &c__1, &w[k + k * w_dim1], &c__1);
if (k > 1) {
i__1 = *n - k + 1;
i__2 = k - 1;
dgemv_("No transpose", &i__1, &i__2, &c_b9, &a[k + a_dim1], lda, &
w[k + w_dim1], ldw, &c_b10, &w[k + k * w_dim1], &c__1, (
ftnlen)12);
}
absakk = (d__1 = w[k + k * w_dim1], abs(d__1));
if (k < *n) {
i__1 = *n - k;
imax = k + idamax_(&i__1, &w[k + 1 + k * w_dim1], &c__1);
colmax = (d__1 = w[imax + k * w_dim1], abs(d__1));
} else {
colmax = 0.;
}
if (max(absakk,colmax) == 0.) {
if (*info == 0) {
*info = k;
}
kp = k;
i__1 = *n - k + 1;
dcopy_(&i__1, &w[k + k * w_dim1], &c__1, &a[k + k * a_dim1], &
c__1);
} else {
if (! (absakk < alpha * colmax)) {
kp = k;
} else {
done = FALSE_;
L72:
i__1 = imax - k;
dcopy_(&i__1, &a[imax + k * a_dim1], lda, &w[k + (k + 1) *
w_dim1], &c__1);
i__1 = *n - imax + 1;
dcopy_(&i__1, &a[imax + imax * a_dim1], &c__1, &w[imax + (k +
1) * w_dim1], &c__1);
if (k > 1) {
i__1 = *n - k + 1;
i__2 = k - 1;
dgemv_("No transpose", &i__1, &i__2, &c_b9, &a[k + a_dim1]
, lda, &w[imax + w_dim1], ldw, &c_b10, &w[k + (k
+ 1) * w_dim1], &c__1, (ftnlen)12);
}
if (imax != k) {
i__1 = imax - k;
jmax = k - 1 + idamax_(&i__1, &w[k + (k + 1) * w_dim1], &
c__1);
rowmax = (d__1 = w[jmax + (k + 1) * w_dim1], abs(d__1));
} else {
rowmax = 0.;
}
if (imax < *n) {
i__1 = *n - imax;
itemp = imax + idamax_(&i__1, &w[imax + 1 + (k + 1) *
w_dim1], &c__1);
dtemp = (d__1 = w[itemp + (k + 1) * w_dim1], abs(d__1));
if (dtemp > rowmax) {
rowmax = dtemp;
jmax = itemp;
}
}
if (! ((d__1 = w[imax + (k + 1) * w_dim1], abs(d__1)) < alpha
* rowmax)) {
kp = imax;
i__1 = *n - k + 1;
dcopy_(&i__1, &w[k + (k + 1) * w_dim1], &c__1, &w[k + k *
w_dim1], &c__1);
done = TRUE_;
} else if (p == jmax || rowmax <= colmax) {
kp = imax;
kstep = 2;
done = TRUE_;
} else {
p = imax;
colmax = rowmax;
imax = jmax;
i__1 = *n - k + 1;
dcopy_(&i__1, &w[k + (k + 1) * w_dim1], &c__1, &w[k + k *
w_dim1], &c__1);
}
if (! done) {
goto L72;
}
}
kk = k + kstep - 1;
if (kstep == 2 && p != k) {
i__1 = p - k;
dcopy_(&i__1, &a[k + k * a_dim1], &c__1, &a[p + k * a_dim1],
lda);
i__1 = *n - p + 1;
dcopy_(&i__1, &a[p + k * a_dim1], &c__1, &a[p + p * a_dim1], &
c__1);
dswap_(&k, &a[k + a_dim1], lda, &a[p + a_dim1], lda);
dswap_(&kk, &w[k + w_dim1], ldw, &w[p + w_dim1], ldw);
}
if (kp != kk) {
a[kp + k * a_dim1] = a[kk + k * a_dim1];
i__1 = kp - k - 1;
dcopy_(&i__1, &a[k + 1 + kk * a_dim1], &c__1, &a[kp + (k + 1)
* a_dim1], lda);
i__1 = *n - kp + 1;
dcopy_(&i__1, &a[kp + kk * a_dim1], &c__1, &a[kp + kp *
a_dim1], &c__1);
dswap_(&kk, &a[kk + a_dim1], lda, &a[kp + a_dim1], lda);
dswap_(&kk, &w[kk + w_dim1], ldw, &w[kp + w_dim1], ldw);
}
if (kstep == 1) {
i__1 = *n - k + 1;
dcopy_(&i__1, &w[k + k * w_dim1], &c__1, &a[k + k * a_dim1], &
c__1);
if (k < *n) {
if ((d__1 = a[k + k * a_dim1], abs(d__1)) >= sfmin) {
r1 = 1. / a[k + k * a_dim1];
i__1 = *n - k;
dscal_(&i__1, &r1, &a[k + 1 + k * a_dim1], &c__1);
} else if (a[k + k * a_dim1] != 0.) {
i__1 = *n;
for (ii = k + 1; ii <= i__1; ++ii) {
a[ii + k * a_dim1] /= a[k + k * a_dim1];
/* L74: */
}
}
}
} else {
if (k < *n - 1) {
d21 = w[k + 1 + k * w_dim1];
d11 = w[k + 1 + (k + 1) * w_dim1] / d21;
d22 = w[k + k * w_dim1] / d21;
t = 1. / (d11 * d22 - 1.);
i__1 = *n;
for (j = k + 2; j <= i__1; ++j) {
a[j + k * a_dim1] = t * ((d11 * w[j + k * w_dim1] - w[
j + (k + 1) * w_dim1]) / d21);
a[j + (k + 1) * a_dim1] = t * ((d22 * w[j + (k + 1) *
w_dim1] - w[j + k * w_dim1]) / d21);
/* L80: */
}
}
a[k + k * a_dim1] = w[k + k * w_dim1];
a[k + 1 + k * a_dim1] = w[k + 1 + k * w_dim1];
a[k + 1 + (k + 1) * a_dim1] = w[k + 1 + (k + 1) * w_dim1];
}
}
if (kstep == 1) {
ipiv[k] = kp;
} else {
ipiv[k] = -p;
ipiv[k + 1] = -kp;
}
k += kstep;
goto L70;
L90:
j = k - 1;
L120:
kstep = 1;
jp1 = 1;
jj = j;
jp2 = ipiv[j];
if (jp2 < 0) {
jp2 = -jp2;
--j;
jp1 = -ipiv[j];
kstep = 2;
}
--j;
if (jp2 != jj && j >= 1) {
dswap_(&j, &a[jp2 + a_dim1], lda, &a[jj + a_dim1], lda);
}
jj = j + 1;
if (jp1 != jj && kstep == 2) {
dswap_(&j, &a[jp1 + a_dim1], lda, &a[jj + a_dim1], lda);
}
if (j >= 1) {
goto L120;
}
*kb = k - 1;
}
return;
}