--- /dev/null
+#include "clapack.h"
+
+/* Table of constant values */
+
+static integer c__0 = 0;
+static doublereal c_b11 = 0.;
+static doublereal c_b12 = 1.;
+static integer c__1 = 1;
+static integer c__2 = 2;
+
+/* Subroutine */ int dlasda_(integer *icompq, integer *smlsiz, integer *n,
+ integer *sqre, doublereal *d__, doublereal *e, doublereal *u, integer
+ *ldu, doublereal *vt, integer *k, doublereal *difl, doublereal *difr,
+ doublereal *z__, doublereal *poles, integer *givptr, integer *givcol,
+ integer *ldgcol, integer *perm, doublereal *givnum, doublereal *c__,
+ doublereal *s, doublereal *work, integer *iwork, integer *info)
+{
+ /* System generated locals */
+ integer givcol_dim1, givcol_offset, perm_dim1, perm_offset, difl_dim1,
+ difl_offset, difr_dim1, difr_offset, givnum_dim1, givnum_offset,
+ poles_dim1, poles_offset, u_dim1, u_offset, vt_dim1, vt_offset,
+ z_dim1, z_offset, i__1, i__2;
+
+ /* Builtin functions */
+ integer pow_ii(integer *, integer *);
+
+ /* Local variables */
+ integer i__, j, m, i1, ic, lf, nd, ll, nl, vf, nr, vl, im1, ncc, nlf, nrf,
+ vfi, iwk, vli, lvl, nru, ndb1, nlp1, lvl2, nrp1;
+ doublereal beta;
+ integer idxq, nlvl;
+ doublereal alpha;
+ integer inode, ndiml, ndimr, idxqi, itemp;
+ extern /* Subroutine */ int dcopy_(integer *, doublereal *, integer *,
+ doublereal *, integer *);
+ integer sqrei;
+ extern /* Subroutine */ int dlasd6_(integer *, integer *, integer *,
+ integer *, doublereal *, doublereal *, doublereal *, doublereal *,
+ doublereal *, integer *, integer *, integer *, integer *,
+ integer *, doublereal *, integer *, doublereal *, doublereal *,
+ doublereal *, doublereal *, integer *, doublereal *, doublereal *,
+ doublereal *, integer *, integer *);
+ integer nwork1, nwork2;
+ extern /* Subroutine */ int dlasdq_(char *, integer *, integer *, integer
+ *, integer *, integer *, doublereal *, doublereal *, doublereal *,
+ integer *, doublereal *, integer *, doublereal *, integer *,
+ doublereal *, integer *), dlasdt_(integer *, integer *,
+ integer *, integer *, integer *, integer *, integer *), dlaset_(
+ char *, integer *, integer *, doublereal *, doublereal *,
+ doublereal *, integer *), xerbla_(char *, integer *);
+ integer smlszp;
+
+
+/* -- LAPACK auxiliary routine (version 3.1) -- */
+/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
+/* November 2006 */
+
+/* .. Scalar Arguments .. */
+/* .. */
+/* .. Array Arguments .. */
+/* .. */
+
+/* Purpose */
+/* ======= */
+
+/* Using a divide and conquer approach, DLASDA computes the singular */
+/* value decomposition (SVD) of a real upper bidiagonal N-by-M matrix */
+/* B with diagonal D and offdiagonal E, where M = N + SQRE. The */
+/* algorithm computes the singular values in the SVD B = U * S * VT. */
+/* The orthogonal matrices U and VT are optionally computed in */
+/* compact form. */
+
+/* A related subroutine, DLASD0, computes the singular values and */
+/* the singular vectors in explicit form. */
+
+/* Arguments */
+/* ========= */
+
+/* ICOMPQ (input) INTEGER */
+/* Specifies whether singular vectors are to be computed */
+/* in compact form, as follows */
+/* = 0: Compute singular values only. */
+/* = 1: Compute singular vectors of upper bidiagonal */
+/* matrix in compact form. */
+
+/* SMLSIZ (input) INTEGER */
+/* The maximum size of the subproblems at the bottom of the */
+/* computation tree. */
+
+/* N (input) INTEGER */
+/* The row dimension of the upper bidiagonal matrix. This is */
+/* also the dimension of the main diagonal array D. */
+
+/* SQRE (input) INTEGER */
+/* Specifies the column dimension of the bidiagonal matrix. */
+/* = 0: The bidiagonal matrix has column dimension M = N; */
+/* = 1: The bidiagonal matrix has column dimension M = N + 1. */
+
+/* D (input/output) DOUBLE PRECISION array, dimension ( N ) */
+/* On entry D contains the main diagonal of the bidiagonal */
+/* matrix. On exit D, if INFO = 0, contains its singular values. */
+
+/* E (input) DOUBLE PRECISION array, dimension ( M-1 ) */
+/* Contains the subdiagonal entries of the bidiagonal matrix. */
+/* On exit, E has been destroyed. */
+
+/* U (output) DOUBLE PRECISION array, */
+/* dimension ( LDU, SMLSIZ ) if ICOMPQ = 1, and not referenced */
+/* if ICOMPQ = 0. If ICOMPQ = 1, on exit, U contains the left */
+/* singular vector matrices of all subproblems at the bottom */
+/* level. */
+
+/* LDU (input) INTEGER, LDU = > N. */
+/* The leading dimension of arrays U, VT, DIFL, DIFR, POLES, */
+/* GIVNUM, and Z. */
+
+/* VT (output) DOUBLE PRECISION array, */
+/* dimension ( LDU, SMLSIZ+1 ) if ICOMPQ = 1, and not referenced */
+/* if ICOMPQ = 0. If ICOMPQ = 1, on exit, VT' contains the right */
+/* singular vector matrices of all subproblems at the bottom */
+/* level. */
+
+/* K (output) INTEGER array, */
+/* dimension ( N ) if ICOMPQ = 1 and dimension 1 if ICOMPQ = 0. */
+/* If ICOMPQ = 1, on exit, K(I) is the dimension of the I-th */
+/* secular equation on the computation tree. */
+
+/* DIFL (output) DOUBLE PRECISION array, dimension ( LDU, NLVL ), */
+/* where NLVL = floor(log_2 (N/SMLSIZ))). */
+
+/* DIFR (output) DOUBLE PRECISION array, */
+/* dimension ( LDU, 2 * NLVL ) if ICOMPQ = 1 and */
+/* dimension ( N ) if ICOMPQ = 0. */
+/* If ICOMPQ = 1, on exit, DIFL(1:N, I) and DIFR(1:N, 2 * I - 1) */
+/* record distances between singular values on the I-th */
+/* level and singular values on the (I -1)-th level, and */
+/* DIFR(1:N, 2 * I ) contains the normalizing factors for */
+/* the right singular vector matrix. See DLASD8 for details. */
+
+/* Z (output) DOUBLE PRECISION array, */
+/* dimension ( LDU, NLVL ) if ICOMPQ = 1 and */
+/* dimension ( N ) if ICOMPQ = 0. */
+/* The first K elements of Z(1, I) contain the components of */
+/* the deflation-adjusted updating row vector for subproblems */
+/* on the I-th level. */
+
+/* POLES (output) DOUBLE PRECISION array, */
+/* dimension ( LDU, 2 * NLVL ) if ICOMPQ = 1, and not referenced */
+/* if ICOMPQ = 0. If ICOMPQ = 1, on exit, POLES(1, 2*I - 1) and */
+/* POLES(1, 2*I) contain the new and old singular values */
+/* involved in the secular equations on the I-th level. */
+
+/* GIVPTR (output) INTEGER array, */
+/* dimension ( N ) if ICOMPQ = 1, and not referenced if */
+/* ICOMPQ = 0. If ICOMPQ = 1, on exit, GIVPTR( I ) records */
+/* the number of Givens rotations performed on the I-th */
+/* problem on the computation tree. */
+
+/* GIVCOL (output) INTEGER array, */
+/* dimension ( LDGCOL, 2 * NLVL ) if ICOMPQ = 1, and not */
+/* referenced if ICOMPQ = 0. If ICOMPQ = 1, on exit, for each I, */
+/* GIVCOL(1, 2 *I - 1) and GIVCOL(1, 2 *I) record the locations */
+/* of Givens rotations performed on the I-th level on the */
+/* computation tree. */
+
+/* LDGCOL (input) INTEGER, LDGCOL = > N. */
+/* The leading dimension of arrays GIVCOL and PERM. */
+
+/* PERM (output) INTEGER array, */
+/* dimension ( LDGCOL, NLVL ) if ICOMPQ = 1, and not referenced */
+/* if ICOMPQ = 0. If ICOMPQ = 1, on exit, PERM(1, I) records */
+/* permutations done on the I-th level of the computation tree. */
+
+/* GIVNUM (output) DOUBLE PRECISION array, */
+/* dimension ( LDU, 2 * NLVL ) if ICOMPQ = 1, and not */
+/* referenced if ICOMPQ = 0. If ICOMPQ = 1, on exit, for each I, */
+/* GIVNUM(1, 2 *I - 1) and GIVNUM(1, 2 *I) record the C- and S- */
+/* values of Givens rotations performed on the I-th level on */
+/* the computation tree. */
+
+/* C (output) DOUBLE PRECISION array, */
+/* dimension ( N ) if ICOMPQ = 1, and dimension 1 if ICOMPQ = 0. */
+/* If ICOMPQ = 1 and the I-th subproblem is not square, on exit, */
+/* C( I ) contains the C-value of a Givens rotation related to */
+/* the right null space of the I-th subproblem. */
+
+/* S (output) DOUBLE PRECISION array, dimension ( N ) if */
+/* ICOMPQ = 1, and dimension 1 if ICOMPQ = 0. If ICOMPQ = 1 */
+/* and the I-th subproblem is not square, on exit, S( I ) */
+/* contains the S-value of a Givens rotation related to */
+/* the right null space of the I-th subproblem. */
+
+/* WORK (workspace) DOUBLE PRECISION array, dimension */
+/* (6 * N + (SMLSIZ + 1)*(SMLSIZ + 1)). */
+
+/* IWORK (workspace) INTEGER array. */
+/* Dimension must be at least (7 * N). */
+
+/* INFO (output) INTEGER */
+/* = 0: successful exit. */
+/* < 0: if INFO = -i, the i-th argument had an illegal value. */
+/* > 0: if INFO = 1, an singular value did not converge */
+
+/* Further Details */
+/* =============== */
+
+/* Based on contributions by */
+/* Ming Gu and Huan Ren, Computer Science Division, University of */
+/* California at Berkeley, USA */
+
+/* ===================================================================== */
+
+/* .. Parameters .. */
+/* .. */
+/* .. Local Scalars .. */
+/* .. */
+/* .. External Subroutines .. */
+/* .. */
+/* .. Executable Statements .. */
+
+/* Test the input parameters. */
+
+ /* Parameter adjustments */
+ --d__;
+ --e;
+ givnum_dim1 = *ldu;
+ givnum_offset = 1 + givnum_dim1;
+ givnum -= givnum_offset;
+ poles_dim1 = *ldu;
+ poles_offset = 1 + poles_dim1;
+ poles -= poles_offset;
+ z_dim1 = *ldu;
+ z_offset = 1 + z_dim1;
+ z__ -= z_offset;
+ difr_dim1 = *ldu;
+ difr_offset = 1 + difr_dim1;
+ difr -= difr_offset;
+ difl_dim1 = *ldu;
+ difl_offset = 1 + difl_dim1;
+ difl -= difl_offset;
+ vt_dim1 = *ldu;
+ vt_offset = 1 + vt_dim1;
+ vt -= vt_offset;
+ u_dim1 = *ldu;
+ u_offset = 1 + u_dim1;
+ u -= u_offset;
+ --k;
+ --givptr;
+ perm_dim1 = *ldgcol;
+ perm_offset = 1 + perm_dim1;
+ perm -= perm_offset;
+ givcol_dim1 = *ldgcol;
+ givcol_offset = 1 + givcol_dim1;
+ givcol -= givcol_offset;
+ --c__;
+ --s;
+ --work;
+ --iwork;
+
+ /* Function Body */
+ *info = 0;
+
+ if (*icompq < 0 || *icompq > 1) {
+ *info = -1;
+ } else if (*smlsiz < 3) {
+ *info = -2;
+ } else if (*n < 0) {
+ *info = -3;
+ } else if (*sqre < 0 || *sqre > 1) {
+ *info = -4;
+ } else if (*ldu < *n + *sqre) {
+ *info = -8;
+ } else if (*ldgcol < *n) {
+ *info = -17;
+ }
+ if (*info != 0) {
+ i__1 = -(*info);
+ xerbla_("DLASDA", &i__1);
+ return 0;
+ }
+
+ m = *n + *sqre;
+
+/* If the input matrix is too small, call DLASDQ to find the SVD. */
+
+ if (*n <= *smlsiz) {
+ if (*icompq == 0) {
+ dlasdq_("U", sqre, n, &c__0, &c__0, &c__0, &d__[1], &e[1], &vt[
+ vt_offset], ldu, &u[u_offset], ldu, &u[u_offset], ldu, &
+ work[1], info);
+ } else {
+ dlasdq_("U", sqre, n, &m, n, &c__0, &d__[1], &e[1], &vt[vt_offset]
+, ldu, &u[u_offset], ldu, &u[u_offset], ldu, &work[1],
+ info);
+ }
+ return 0;
+ }
+
+/* Book-keeping and set up the computation tree. */
+
+ inode = 1;
+ ndiml = inode + *n;
+ ndimr = ndiml + *n;
+ idxq = ndimr + *n;
+ iwk = idxq + *n;
+
+ ncc = 0;
+ nru = 0;
+
+ smlszp = *smlsiz + 1;
+ vf = 1;
+ vl = vf + m;
+ nwork1 = vl + m;
+ nwork2 = nwork1 + smlszp * smlszp;
+
+ dlasdt_(n, &nlvl, &nd, &iwork[inode], &iwork[ndiml], &iwork[ndimr],
+ smlsiz);
+
+/* for the nodes on bottom level of the tree, solve */
+/* their subproblems by DLASDQ. */
+
+ ndb1 = (nd + 1) / 2;
+ i__1 = nd;
+ for (i__ = ndb1; i__ <= i__1; ++i__) {
+
+/* IC : center row of each node */
+/* NL : number of rows of left subproblem */
+/* NR : number of rows of right subproblem */
+/* NLF: starting row of the left subproblem */
+/* NRF: starting row of the right subproblem */
+
+ i1 = i__ - 1;
+ ic = iwork[inode + i1];
+ nl = iwork[ndiml + i1];
+ nlp1 = nl + 1;
+ nr = iwork[ndimr + i1];
+ nlf = ic - nl;
+ nrf = ic + 1;
+ idxqi = idxq + nlf - 2;
+ vfi = vf + nlf - 1;
+ vli = vl + nlf - 1;
+ sqrei = 1;
+ if (*icompq == 0) {
+ dlaset_("A", &nlp1, &nlp1, &c_b11, &c_b12, &work[nwork1], &smlszp);
+ dlasdq_("U", &sqrei, &nl, &nlp1, &nru, &ncc, &d__[nlf], &e[nlf], &
+ work[nwork1], &smlszp, &work[nwork2], &nl, &work[nwork2],
+ &nl, &work[nwork2], info);
+ itemp = nwork1 + nl * smlszp;
+ dcopy_(&nlp1, &work[nwork1], &c__1, &work[vfi], &c__1);
+ dcopy_(&nlp1, &work[itemp], &c__1, &work[vli], &c__1);
+ } else {
+ dlaset_("A", &nl, &nl, &c_b11, &c_b12, &u[nlf + u_dim1], ldu);
+ dlaset_("A", &nlp1, &nlp1, &c_b11, &c_b12, &vt[nlf + vt_dim1],
+ ldu);
+ dlasdq_("U", &sqrei, &nl, &nlp1, &nl, &ncc, &d__[nlf], &e[nlf], &
+ vt[nlf + vt_dim1], ldu, &u[nlf + u_dim1], ldu, &u[nlf +
+ u_dim1], ldu, &work[nwork1], info);
+ dcopy_(&nlp1, &vt[nlf + vt_dim1], &c__1, &work[vfi], &c__1);
+ dcopy_(&nlp1, &vt[nlf + nlp1 * vt_dim1], &c__1, &work[vli], &c__1)
+ ;
+ }
+ if (*info != 0) {
+ return 0;
+ }
+ i__2 = nl;
+ for (j = 1; j <= i__2; ++j) {
+ iwork[idxqi + j] = j;
+/* L10: */
+ }
+ if (i__ == nd && *sqre == 0) {
+ sqrei = 0;
+ } else {
+ sqrei = 1;
+ }
+ idxqi += nlp1;
+ vfi += nlp1;
+ vli += nlp1;
+ nrp1 = nr + sqrei;
+ if (*icompq == 0) {
+ dlaset_("A", &nrp1, &nrp1, &c_b11, &c_b12, &work[nwork1], &smlszp);
+ dlasdq_("U", &sqrei, &nr, &nrp1, &nru, &ncc, &d__[nrf], &e[nrf], &
+ work[nwork1], &smlszp, &work[nwork2], &nr, &work[nwork2],
+ &nr, &work[nwork2], info);
+ itemp = nwork1 + (nrp1 - 1) * smlszp;
+ dcopy_(&nrp1, &work[nwork1], &c__1, &work[vfi], &c__1);
+ dcopy_(&nrp1, &work[itemp], &c__1, &work[vli], &c__1);
+ } else {
+ dlaset_("A", &nr, &nr, &c_b11, &c_b12, &u[nrf + u_dim1], ldu);
+ dlaset_("A", &nrp1, &nrp1, &c_b11, &c_b12, &vt[nrf + vt_dim1],
+ ldu);
+ dlasdq_("U", &sqrei, &nr, &nrp1, &nr, &ncc, &d__[nrf], &e[nrf], &
+ vt[nrf + vt_dim1], ldu, &u[nrf + u_dim1], ldu, &u[nrf +
+ u_dim1], ldu, &work[nwork1], info);
+ dcopy_(&nrp1, &vt[nrf + vt_dim1], &c__1, &work[vfi], &c__1);
+ dcopy_(&nrp1, &vt[nrf + nrp1 * vt_dim1], &c__1, &work[vli], &c__1)
+ ;
+ }
+ if (*info != 0) {
+ return 0;
+ }
+ i__2 = nr;
+ for (j = 1; j <= i__2; ++j) {
+ iwork[idxqi + j] = j;
+/* L20: */
+ }
+/* L30: */
+ }
+
+/* Now conquer each subproblem bottom-up. */
+
+ j = pow_ii(&c__2, &nlvl);
+ for (lvl = nlvl; lvl >= 1; --lvl) {
+ lvl2 = (lvl << 1) - 1;
+
+/* Find the first node LF and last node LL on */
+/* the current level LVL. */
+
+ if (lvl == 1) {
+ lf = 1;
+ ll = 1;
+ } else {
+ i__1 = lvl - 1;
+ lf = pow_ii(&c__2, &i__1);
+ ll = (lf << 1) - 1;
+ }
+ i__1 = ll;
+ for (i__ = lf; i__ <= i__1; ++i__) {
+ im1 = i__ - 1;
+ ic = iwork[inode + im1];
+ nl = iwork[ndiml + im1];
+ nr = iwork[ndimr + im1];
+ nlf = ic - nl;
+ nrf = ic + 1;
+ if (i__ == ll) {
+ sqrei = *sqre;
+ } else {
+ sqrei = 1;
+ }
+ vfi = vf + nlf - 1;
+ vli = vl + nlf - 1;
+ idxqi = idxq + nlf - 1;
+ alpha = d__[ic];
+ beta = e[ic];
+ if (*icompq == 0) {
+ dlasd6_(icompq, &nl, &nr, &sqrei, &d__[nlf], &work[vfi], &
+ work[vli], &alpha, &beta, &iwork[idxqi], &perm[
+ perm_offset], &givptr[1], &givcol[givcol_offset],
+ ldgcol, &givnum[givnum_offset], ldu, &poles[
+ poles_offset], &difl[difl_offset], &difr[difr_offset],
+ &z__[z_offset], &k[1], &c__[1], &s[1], &work[nwork1],
+ &iwork[iwk], info);
+ } else {
+ --j;
+ dlasd6_(icompq, &nl, &nr, &sqrei, &d__[nlf], &work[vfi], &
+ work[vli], &alpha, &beta, &iwork[idxqi], &perm[nlf +
+ lvl * perm_dim1], &givptr[j], &givcol[nlf + lvl2 *
+ givcol_dim1], ldgcol, &givnum[nlf + lvl2 *
+ givnum_dim1], ldu, &poles[nlf + lvl2 * poles_dim1], &
+ difl[nlf + lvl * difl_dim1], &difr[nlf + lvl2 *
+ difr_dim1], &z__[nlf + lvl * z_dim1], &k[j], &c__[j],
+ &s[j], &work[nwork1], &iwork[iwk], info);
+ }
+ if (*info != 0) {
+ return 0;
+ }
+/* L40: */
+ }
+/* L50: */
+ }
+
+ return 0;
+
+/* End of DLASDA */
+
+} /* dlasda_ */