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authorshmel1k <shmel1k@ydb.tech>2022-09-02 12:44:59 +0300
committershmel1k <shmel1k@ydb.tech>2022-09-02 12:44:59 +0300
commit90d450f74722da7859d6f510a869f6c6908fd12f (patch)
tree538c718dedc76cdfe37ad6d01ff250dd930d9278 /contrib/libs/clapack/sgesvj.c
parent01f64c1ecd0d4ffa9e3a74478335f1745f26cc75 (diff)
downloadydb-90d450f74722da7859d6f510a869f6c6908fd12f.tar.gz
[] add metering mode to CLI
Diffstat (limited to 'contrib/libs/clapack/sgesvj.c')
-rw-r--r--contrib/libs/clapack/sgesvj.c1785
1 files changed, 1785 insertions, 0 deletions
diff --git a/contrib/libs/clapack/sgesvj.c b/contrib/libs/clapack/sgesvj.c
new file mode 100644
index 0000000000..0510c9991e
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+++ b/contrib/libs/clapack/sgesvj.c
@@ -0,0 +1,1785 @@
+/* sgesvj.f -- translated by f2c (version 20061008).
+ 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"
+#include "blaswrap.h"
+
+/* Table of constant values */
+
+static real c_b17 = 0.f;
+static real c_b18 = 1.f;
+static integer c__1 = 1;
+static integer c__0 = 0;
+static integer c__2 = 2;
+
+/* Subroutine */ int sgesvj_(char *joba, char *jobu, char *jobv, integer *m,
+ integer *n, real *a, integer *lda, real *sva, integer *mv, real *v,
+ integer *ldv, real *work, integer *lwork, integer *info)
+{
+ /* System generated locals */
+ integer a_dim1, a_offset, v_dim1, v_offset, i__1, i__2, i__3, i__4, i__5;
+ real r__1, r__2;
+
+ /* Builtin functions */
+ double sqrt(doublereal), r_sign(real *, real *);
+
+ /* Local variables */
+ real bigtheta;
+ integer pskipped, i__, p, q;
+ real t;
+ integer n2, n4;
+ real rootsfmin;
+ integer n34;
+ real cs, sn;
+ integer ir1, jbc;
+ real big;
+ integer kbl, igl, ibr, jgl, nbl;
+ real tol;
+ integer mvl;
+ real aapp, aapq, aaqq, ctol;
+ integer ierr;
+ extern doublereal sdot_(integer *, real *, integer *, real *, integer *);
+ real aapp0, temp1;
+ extern doublereal snrm2_(integer *, real *, integer *);
+ real scale, large, apoaq, aqoap;
+ extern logical lsame_(char *, char *);
+ real theta;
+ extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *);
+ real small, sfmin;
+ logical lsvec;
+ real fastr[5];
+ logical applv, rsvec, uctol, lower, upper;
+ extern /* Subroutine */ int scopy_(integer *, real *, integer *, real *,
+ integer *);
+ logical rotok;
+ extern /* Subroutine */ int sswap_(integer *, real *, integer *, real *,
+ integer *), saxpy_(integer *, real *, real *, integer *, real *,
+ integer *), srotm_(integer *, real *, integer *, real *, integer *
+, real *), sgsvj0_(char *, integer *, integer *, real *, integer *
+, real *, real *, integer *, real *, integer *, real *, real *,
+ real *, integer *, real *, integer *, integer *), sgsvj1_(
+ char *, integer *, integer *, integer *, real *, integer *, real *
+, real *, integer *, real *, integer *, real *, real *, real *,
+ integer *, real *, integer *, integer *);
+ extern doublereal slamch_(char *);
+ extern /* Subroutine */ int xerbla_(char *, integer *);
+ integer ijblsk, swband;
+ extern /* Subroutine */ int slascl_(char *, integer *, integer *, real *,
+ real *, integer *, integer *, real *, integer *, integer *);
+ extern integer isamax_(integer *, real *, integer *);
+ integer blskip;
+ real mxaapq;
+ extern /* Subroutine */ int slaset_(char *, integer *, integer *, real *,
+ real *, real *, integer *);
+ real thsign;
+ extern /* Subroutine */ int slassq_(integer *, real *, integer *, real *,
+ real *);
+ real mxsinj;
+ integer emptsw, notrot, iswrot, lkahead;
+ logical goscale, noscale;
+ real rootbig, epsilon, rooteps;
+ integer rowskip;
+ real roottol;
+
+
+/* -- LAPACK routine (version 3.2) -- */
+
+/* -- Contributed by Zlatko Drmac of the University of Zagreb and -- */
+/* -- Kresimir Veselic of the Fernuniversitaet Hagen -- */
+/* -- November 2008 -- */
+
+/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
+/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
+
+/* This routine is also part of SIGMA (version 1.23, October 23. 2008.) */
+/* SIGMA is a library of algorithms for highly accurate algorithms for */
+/* computation of SVD, PSVD, QSVD, (H,K)-SVD, and for solution of the */
+/* eigenvalue problems Hx = lambda M x, H M x = lambda x with H, M > 0. */
+
+/* -#- Scalar Arguments -#- */
+
+
+/* -#- Array Arguments -#- */
+
+/* .. */
+
+/* Purpose */
+/* ~~~~~~~ */
+/* SGESVJ computes the singular value decomposition (SVD) of a real */
+/* M-by-N matrix A, where M >= N. The SVD of A is written as */
+/* [++] [xx] [x0] [xx] */
+/* A = U * SIGMA * V^t, [++] = [xx] * [ox] * [xx] */
+/* [++] [xx] */
+/* where SIGMA is an N-by-N diagonal matrix, U is an M-by-N orthonormal */
+/* matrix, and V is an N-by-N orthogonal matrix. The diagonal elements */
+/* of SIGMA are the singular values of A. The columns of U and V are the */
+/* left and the right singular vectors of A, respectively. */
+
+/* Further Details */
+/* ~~~~~~~~~~~~~~~ */
+/* The orthogonal N-by-N matrix V is obtained as a product of Jacobi plane */
+/* rotations. The rotations are implemented as fast scaled rotations of */
+/* Anda and Park [1]. In the case of underflow of the Jacobi angle, a */
+/* modified Jacobi transformation of Drmac [4] is used. Pivot strategy uses */
+/* column interchanges of de Rijk [2]. The relative accuracy of the computed */
+/* singular values and the accuracy of the computed singular vectors (in */
+/* angle metric) is as guaranteed by the theory of Demmel and Veselic [3]. */
+/* The condition number that determines the accuracy in the full rank case */
+/* is essentially min_{D=diag} kappa(A*D), where kappa(.) is the */
+/* spectral condition number. The best performance of this Jacobi SVD */
+/* procedure is achieved if used in an accelerated version of Drmac and */
+/* Veselic [5,6], and it is the kernel routine in the SIGMA library [7]. */
+/* Some tunning parameters (marked with [TP]) are available for the */
+/* implementer. */
+/* The computational range for the nonzero singular values is the machine */
+/* number interval ( UNDERFLOW , OVERFLOW ). In extreme cases, even */
+/* denormalized singular values can be computed with the corresponding */
+/* gradual loss of accurate digits. */
+
+/* Contributors */
+/* ~~~~~~~~~~~~ */
+/* Zlatko Drmac (Zagreb, Croatia) and Kresimir Veselic (Hagen, Germany) */
+
+/* References */
+/* ~~~~~~~~~~ */
+/* [1] A. A. Anda and H. Park: Fast plane rotations with dynamic scaling. */
+/* SIAM J. matrix Anal. Appl., Vol. 15 (1994), pp. 162-174. */
+/* [2] P. P. M. De Rijk: A one-sided Jacobi algorithm for computing the */
+/* singular value decomposition on a vector computer. */
+/* SIAM J. Sci. Stat. Comp., Vol. 10 (1998), pp. 359-371. */
+/* [3] J. Demmel and K. Veselic: Jacobi method is more accurate than QR. */
+/* [4] Z. Drmac: Implementation of Jacobi rotations for accurate singular */
+/* value computation in floating point arithmetic. */
+/* SIAM J. Sci. Comp., Vol. 18 (1997), pp. 1200-1222. */
+/* [5] Z. Drmac and K. Veselic: New fast and accurate Jacobi SVD algorithm I. */
+/* SIAM J. Matrix Anal. Appl. Vol. 35, No. 2 (2008), pp. 1322-1342. */
+/* LAPACK Working note 169. */
+/* [6] Z. Drmac and K. Veselic: New fast and accurate Jacobi SVD algorithm II. */
+/* SIAM J. Matrix Anal. Appl. Vol. 35, No. 2 (2008), pp. 1343-1362. */
+/* LAPACK Working note 170. */
+/* [7] Z. Drmac: SIGMA - mathematical software library for accurate SVD, PSV, */
+/* QSVD, (H,K)-SVD computations. */
+/* Department of Mathematics, University of Zagreb, 2008. */
+
+/* Bugs, Examples and Comments */
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+/* Please report all bugs and send interesting test examples and comments to */
+/* drmac@math.hr. Thank you. */
+
+/* Arguments */
+/* ~~~~~~~~~ */
+
+/* JOBA (input) CHARACTER* 1 */
+/* Specifies the structure of A. */
+/* = 'L': The input matrix A is lower triangular; */
+/* = 'U': The input matrix A is upper triangular; */
+/* = 'G': The input matrix A is general M-by-N matrix, M >= N. */
+
+/* JOBU (input) CHARACTER*1 */
+/* Specifies whether to compute the left singular vectors */
+/* (columns of U): */
+
+/* = 'U': The left singular vectors corresponding to the nonzero */
+/* singular values are computed and returned in the leading */
+/* columns of A. See more details in the description of A. */
+/* The default numerical orthogonality threshold is set to */
+/* approximately TOL=CTOL*EPS, CTOL=SQRT(M), EPS=SLAMCH('E'). */
+/* = 'C': Analogous to JOBU='U', except that user can control the */
+/* level of numerical orthogonality of the computed left */
+/* singular vectors. TOL can be set to TOL = CTOL*EPS, where */
+/* CTOL is given on input in the array WORK. */
+/* No CTOL smaller than ONE is allowed. CTOL greater */
+/* than 1 / EPS is meaningless. The option 'C' */
+/* can be used if M*EPS is satisfactory orthogonality */
+/* of the computed left singular vectors, so CTOL=M could */
+/* save few sweeps of Jacobi rotations. */
+/* See the descriptions of A and WORK(1). */
+/* = 'N': The matrix U is not computed. However, see the */
+/* description of A. */
+
+/* JOBV (input) CHARACTER*1 */
+/* Specifies whether to compute the right singular vectors, that */
+/* is, the matrix V: */
+/* = 'V' : the matrix V is computed and returned in the array V */
+/* = 'A' : the Jacobi rotations are applied to the MV-by-N */
+/* array V. In other words, the right singular vector */
+/* matrix V is not computed explicitly; instead it is */
+/* applied to an MV-by-N matrix initially stored in the */
+/* first MV rows of V. */
+/* = 'N' : the matrix V is not computed and the array V is not */
+/* referenced */
+
+/* M (input) INTEGER */
+/* The number of rows of the input matrix A. M >= 0. */
+
+/* N (input) INTEGER */
+/* The number of columns of the input matrix A. */
+/* M >= N >= 0. */
+
+/* A (input/output) REAL array, dimension (LDA,N) */
+/* On entry, the M-by-N matrix A. */
+/* On exit, */
+/* If JOBU .EQ. 'U' .OR. JOBU .EQ. 'C': */
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+/* If INFO .EQ. 0, */
+/* ~~~~~~~~~~~~~~~ */
+/* RANKA orthonormal columns of U are returned in the */
+/* leading RANKA columns of the array A. Here RANKA <= N */
+/* is the number of computed singular values of A that are */
+/* above the underflow threshold SLAMCH('S'). The singular */
+/* vectors corresponding to underflowed or zero singular */
+/* values are not computed. The value of RANKA is returned */
+/* in the array WORK as RANKA=NINT(WORK(2)). Also see the */
+/* descriptions of SVA and WORK. The computed columns of U */
+/* are mutually numerically orthogonal up to approximately */
+/* TOL=SQRT(M)*EPS (default); or TOL=CTOL*EPS (JOBU.EQ.'C'), */
+/* see the description of JOBU. */
+/* If INFO .GT. 0, */
+/* ~~~~~~~~~~~~~~~ */
+/* the procedure SGESVJ did not converge in the given number */
+/* of iterations (sweeps). In that case, the computed */
+/* columns of U may not be orthogonal up to TOL. The output */
+/* U (stored in A), SIGMA (given by the computed singular */
+/* values in SVA(1:N)) and V is still a decomposition of the */
+/* input matrix A in the sense that the residual */
+/* ||A-SCALE*U*SIGMA*V^T||_2 / ||A||_2 is small. */
+
+/* If JOBU .EQ. 'N': */
+/* ~~~~~~~~~~~~~~~~~ */
+/* If INFO .EQ. 0 */
+/* ~~~~~~~~~~~~~~ */
+/* Note that the left singular vectors are 'for free' in the */
+/* one-sided Jacobi SVD algorithm. However, if only the */
+/* singular values are needed, the level of numerical */
+/* orthogonality of U is not an issue and iterations are */
+/* stopped when the columns of the iterated matrix are */
+/* numerically orthogonal up to approximately M*EPS. Thus, */
+/* on exit, A contains the columns of U scaled with the */
+/* corresponding singular values. */
+/* If INFO .GT. 0, */
+/* ~~~~~~~~~~~~~~~ */
+/* the procedure SGESVJ did not converge in the given number */
+/* of iterations (sweeps). */
+
+/* LDA (input) INTEGER */
+/* The leading dimension of the array A. LDA >= max(1,M). */
+
+/* SVA (workspace/output) REAL array, dimension (N) */
+/* On exit, */
+/* If INFO .EQ. 0, */
+/* ~~~~~~~~~~~~~~~ */
+/* depending on the value SCALE = WORK(1), we have: */
+/* If SCALE .EQ. ONE: */
+/* ~~~~~~~~~~~~~~~~~~ */
+/* SVA(1:N) contains the computed singular values of A. */
+/* During the computation SVA contains the Euclidean column */
+/* norms of the iterated matrices in the array A. */
+/* If SCALE .NE. ONE: */
+/* ~~~~~~~~~~~~~~~~~~ */
+/* The singular values of A are SCALE*SVA(1:N), and this */
+/* factored representation is due to the fact that some of the */
+/* singular values of A might underflow or overflow. */
+
+/* If INFO .GT. 0, */
+/* ~~~~~~~~~~~~~~~ */
+/* the procedure SGESVJ did not converge in the given number of */
+/* iterations (sweeps) and SCALE*SVA(1:N) may not be accurate. */
+
+/* MV (input) INTEGER */
+/* If JOBV .EQ. 'A', then the product of Jacobi rotations in SGESVJ */
+/* is applied to the first MV rows of V. See the description of JOBV. */
+
+/* V (input/output) REAL array, dimension (LDV,N) */
+/* If JOBV = 'V', then V contains on exit the N-by-N matrix of */
+/* the right singular vectors; */
+/* If JOBV = 'A', then V contains the product of the computed right */
+/* singular vector matrix and the initial matrix in */
+/* the array V. */
+/* If JOBV = 'N', then V is not referenced. */
+
+/* LDV (input) INTEGER */
+/* The leading dimension of the array V, LDV .GE. 1. */
+/* If JOBV .EQ. 'V', then LDV .GE. max(1,N). */
+/* If JOBV .EQ. 'A', then LDV .GE. max(1,MV) . */
+
+/* WORK (input/workspace/output) REAL array, dimension max(4,M+N). */
+/* On entry, */
+/* If JOBU .EQ. 'C', */
+/* ~~~~~~~~~~~~~~~~~ */
+/* WORK(1) = CTOL, where CTOL defines the threshold for convergence. */
+/* The process stops if all columns of A are mutually */
+/* orthogonal up to CTOL*EPS, EPS=SLAMCH('E'). */
+/* It is required that CTOL >= ONE, i.e. it is not */
+/* allowed to force the routine to obtain orthogonality */
+/* below EPSILON. */
+/* On exit, */
+/* WORK(1) = SCALE is the scaling factor such that SCALE*SVA(1:N) */
+/* are the computed singular vcalues of A. */
+/* (See description of SVA().) */
+/* WORK(2) = NINT(WORK(2)) is the number of the computed nonzero */
+/* singular values. */
+/* WORK(3) = NINT(WORK(3)) is the number of the computed singular */
+/* values that are larger than the underflow threshold. */
+/* WORK(4) = NINT(WORK(4)) is the number of sweeps of Jacobi */
+/* rotations needed for numerical convergence. */
+/* WORK(5) = max_{i.NE.j} |COS(A(:,i),A(:,j))| in the last sweep. */
+/* This is useful information in cases when SGESVJ did */
+/* not converge, as it can be used to estimate whether */
+/* the output is stil useful and for post festum analysis. */
+/* WORK(6) = the largest absolute value over all sines of the */
+/* Jacobi rotation angles in the last sweep. It can be */
+/* useful for a post festum analysis. */
+
+/* LWORK length of WORK, WORK >= MAX(6,M+N) */
+
+/* INFO (output) INTEGER */
+/* = 0 : successful exit. */
+/* < 0 : if INFO = -i, then the i-th argument had an illegal value */
+/* > 0 : SGESVJ did not converge in the maximal allowed number (30) */
+/* of sweeps. The output may still be useful. See the */
+/* description of WORK. */
+
+/* Local Parameters */
+
+
+/* Local Scalars */
+
+
+/* Local Arrays */
+
+
+/* Intrinsic Functions */
+
+
+/* External Functions */
+/* .. from BLAS */
+/* .. from LAPACK */
+
+/* External Subroutines */
+/* .. from BLAS */
+/* .. from LAPACK */
+
+
+/* Test the input arguments */
+
+ /* Parameter adjustments */
+ --sva;
+ a_dim1 = *lda;
+ a_offset = 1 + a_dim1;
+ a -= a_offset;
+ v_dim1 = *ldv;
+ v_offset = 1 + v_dim1;
+ v -= v_offset;
+ --work;
+
+ /* Function Body */
+ lsvec = lsame_(jobu, "U");
+ uctol = lsame_(jobu, "C");
+ rsvec = lsame_(jobv, "V");
+ applv = lsame_(jobv, "A");
+ upper = lsame_(joba, "U");
+ lower = lsame_(joba, "L");
+
+ if (! (upper || lower || lsame_(joba, "G"))) {
+ *info = -1;
+ } else if (! (lsvec || uctol || lsame_(jobu, "N")))
+ {
+ *info = -2;
+ } else if (! (rsvec || applv || lsame_(jobv, "N")))
+ {
+ *info = -3;
+ } else if (*m < 0) {
+ *info = -4;
+ } else if (*n < 0 || *n > *m) {
+ *info = -5;
+ } else if (*lda < *m) {
+ *info = -7;
+ } else if (*mv < 0) {
+ *info = -9;
+ } else if (rsvec && *ldv < *n || applv && *ldv < *mv) {
+ *info = -11;
+ } else if (uctol && work[1] <= 1.f) {
+ *info = -12;
+ } else /* if(complicated condition) */ {
+/* Computing MAX */
+ i__1 = *m + *n;
+ if (*lwork < max(i__1,6)) {
+ *info = -13;
+ } else {
+ *info = 0;
+ }
+ }
+
+/* #:( */
+ if (*info != 0) {
+ i__1 = -(*info);
+ xerbla_("SGESVJ", &i__1);
+ return 0;
+ }
+
+/* #:) Quick return for void matrix */
+
+ if (*m == 0 || *n == 0) {
+ return 0;
+ }
+
+/* Set numerical parameters */
+/* The stopping criterion for Jacobi rotations is */
+
+/* max_{i<>j}|A(:,i)^T * A(:,j)|/(||A(:,i)||*||A(:,j)||) < CTOL*EPS */
+
+/* where EPS is the round-off and CTOL is defined as follows: */
+
+ if (uctol) {
+/* ... user controlled */
+ ctol = work[1];
+ } else {
+/* ... default */
+ if (lsvec || rsvec || applv) {
+ ctol = sqrt((real) (*m));
+ } else {
+ ctol = (real) (*m);
+ }
+ }
+/* ... and the machine dependent parameters are */
+/* [!] (Make sure that SLAMCH() works properly on the target machine.) */
+
+ epsilon = slamch_("Epsilon");
+ rooteps = sqrt(epsilon);
+ sfmin = slamch_("SafeMinimum");
+ rootsfmin = sqrt(sfmin);
+ small = sfmin / epsilon;
+ big = slamch_("Overflow");
+ rootbig = 1.f / rootsfmin;
+ large = big / sqrt((real) (*m * *n));
+ bigtheta = 1.f / rooteps;
+
+ tol = ctol * epsilon;
+ roottol = sqrt(tol);
+
+ if ((real) (*m) * epsilon >= 1.f) {
+ *info = -5;
+ i__1 = -(*info);
+ xerbla_("SGESVJ", &i__1);
+ return 0;
+ }
+
+/* Initialize the right singular vector matrix. */
+
+ if (rsvec) {
+ mvl = *n;
+ slaset_("A", &mvl, n, &c_b17, &c_b18, &v[v_offset], ldv);
+ } else if (applv) {
+ mvl = *mv;
+ }
+ rsvec = rsvec || applv;
+
+/* Initialize SVA( 1:N ) = ( ||A e_i||_2, i = 1:N ) */
+/* (!) If necessary, scale A to protect the largest singular value */
+/* from overflow. It is possible that saving the largest singular */
+/* value destroys the information about the small ones. */
+/* This initial scaling is almost minimal in the sense that the */
+/* goal is to make sure that no column norm overflows, and that */
+/* SQRT(N)*max_i SVA(i) does not overflow. If INFinite entries */
+/* in A are detected, the procedure returns with INFO=-6. */
+
+ scale = 1.f / sqrt((real) (*m) * (real) (*n));
+ noscale = TRUE_;
+ goscale = TRUE_;
+
+ if (lower) {
+/* the input matrix is M-by-N lower triangular (trapezoidal) */
+ i__1 = *n;
+ for (p = 1; p <= i__1; ++p) {
+ aapp = 0.f;
+ aaqq = 0.f;
+ i__2 = *m - p + 1;
+ slassq_(&i__2, &a[p + p * a_dim1], &c__1, &aapp, &aaqq);
+ if (aapp > big) {
+ *info = -6;
+ i__2 = -(*info);
+ xerbla_("SGESVJ", &i__2);
+ return 0;
+ }
+ aaqq = sqrt(aaqq);
+ if (aapp < big / aaqq && noscale) {
+ sva[p] = aapp * aaqq;
+ } else {
+ noscale = FALSE_;
+ sva[p] = aapp * (aaqq * scale);
+ if (goscale) {
+ goscale = FALSE_;
+ i__2 = p - 1;
+ for (q = 1; q <= i__2; ++q) {
+ sva[q] *= scale;
+/* L1873: */
+ }
+ }
+ }
+/* L1874: */
+ }
+ } else if (upper) {
+/* the input matrix is M-by-N upper triangular (trapezoidal) */
+ i__1 = *n;
+ for (p = 1; p <= i__1; ++p) {
+ aapp = 0.f;
+ aaqq = 0.f;
+ slassq_(&p, &a[p * a_dim1 + 1], &c__1, &aapp, &aaqq);
+ if (aapp > big) {
+ *info = -6;
+ i__2 = -(*info);
+ xerbla_("SGESVJ", &i__2);
+ return 0;
+ }
+ aaqq = sqrt(aaqq);
+ if (aapp < big / aaqq && noscale) {
+ sva[p] = aapp * aaqq;
+ } else {
+ noscale = FALSE_;
+ sva[p] = aapp * (aaqq * scale);
+ if (goscale) {
+ goscale = FALSE_;
+ i__2 = p - 1;
+ for (q = 1; q <= i__2; ++q) {
+ sva[q] *= scale;
+/* L2873: */
+ }
+ }
+ }
+/* L2874: */
+ }
+ } else {
+/* the input matrix is M-by-N general dense */
+ i__1 = *n;
+ for (p = 1; p <= i__1; ++p) {
+ aapp = 0.f;
+ aaqq = 0.f;
+ slassq_(m, &a[p * a_dim1 + 1], &c__1, &aapp, &aaqq);
+ if (aapp > big) {
+ *info = -6;
+ i__2 = -(*info);
+ xerbla_("SGESVJ", &i__2);
+ return 0;
+ }
+ aaqq = sqrt(aaqq);
+ if (aapp < big / aaqq && noscale) {
+ sva[p] = aapp * aaqq;
+ } else {
+ noscale = FALSE_;
+ sva[p] = aapp * (aaqq * scale);
+ if (goscale) {
+ goscale = FALSE_;
+ i__2 = p - 1;
+ for (q = 1; q <= i__2; ++q) {
+ sva[q] *= scale;
+/* L3873: */
+ }
+ }
+ }
+/* L3874: */
+ }
+ }
+
+ if (noscale) {
+ scale = 1.f;
+ }
+
+/* Move the smaller part of the spectrum from the underflow threshold */
+/* (!) Start by determining the position of the nonzero entries of the */
+/* array SVA() relative to ( SFMIN, BIG ). */
+
+ aapp = 0.f;
+ aaqq = big;
+ i__1 = *n;
+ for (p = 1; p <= i__1; ++p) {
+ if (sva[p] != 0.f) {
+/* Computing MIN */
+ r__1 = aaqq, r__2 = sva[p];
+ aaqq = dmin(r__1,r__2);
+ }
+/* Computing MAX */
+ r__1 = aapp, r__2 = sva[p];
+ aapp = dmax(r__1,r__2);
+/* L4781: */
+ }
+
+/* #:) Quick return for zero matrix */
+
+ if (aapp == 0.f) {
+ if (lsvec) {
+ slaset_("G", m, n, &c_b17, &c_b18, &a[a_offset], lda);
+ }
+ work[1] = 1.f;
+ work[2] = 0.f;
+ work[3] = 0.f;
+ work[4] = 0.f;
+ work[5] = 0.f;
+ work[6] = 0.f;
+ return 0;
+ }
+
+/* #:) Quick return for one-column matrix */
+
+ if (*n == 1) {
+ if (lsvec) {
+ slascl_("G", &c__0, &c__0, &sva[1], &scale, m, &c__1, &a[a_dim1 +
+ 1], lda, &ierr);
+ }
+ work[1] = 1.f / scale;
+ if (sva[1] >= sfmin) {
+ work[2] = 1.f;
+ } else {
+ work[2] = 0.f;
+ }
+ work[3] = 0.f;
+ work[4] = 0.f;
+ work[5] = 0.f;
+ work[6] = 0.f;
+ return 0;
+ }
+
+/* Protect small singular values from underflow, and try to */
+/* avoid underflows/overflows in computing Jacobi rotations. */
+
+ sn = sqrt(sfmin / epsilon);
+ temp1 = sqrt(big / (real) (*n));
+ if (aapp <= sn || aaqq >= temp1 || sn <= aaqq && aapp <= temp1) {
+/* Computing MIN */
+ r__1 = big, r__2 = temp1 / aapp;
+ temp1 = dmin(r__1,r__2);
+/* AAQQ = AAQQ*TEMP1 */
+/* AAPP = AAPP*TEMP1 */
+ } else if (aaqq <= sn && aapp <= temp1) {
+/* Computing MIN */
+ r__1 = sn / aaqq, r__2 = big / (aapp * sqrt((real) (*n)));
+ temp1 = dmin(r__1,r__2);
+/* AAQQ = AAQQ*TEMP1 */
+/* AAPP = AAPP*TEMP1 */
+ } else if (aaqq >= sn && aapp >= temp1) {
+/* Computing MAX */
+ r__1 = sn / aaqq, r__2 = temp1 / aapp;
+ temp1 = dmax(r__1,r__2);
+/* AAQQ = AAQQ*TEMP1 */
+/* AAPP = AAPP*TEMP1 */
+ } else if (aaqq <= sn && aapp >= temp1) {
+/* Computing MIN */
+ r__1 = sn / aaqq, r__2 = big / (sqrt((real) (*n)) * aapp);
+ temp1 = dmin(r__1,r__2);
+/* AAQQ = AAQQ*TEMP1 */
+/* AAPP = AAPP*TEMP1 */
+ } else {
+ temp1 = 1.f;
+ }
+
+/* Scale, if necessary */
+
+ if (temp1 != 1.f) {
+ slascl_("G", &c__0, &c__0, &c_b18, &temp1, n, &c__1, &sva[1], n, &
+ ierr);
+ }
+ scale = temp1 * scale;
+ if (scale != 1.f) {
+ slascl_(joba, &c__0, &c__0, &c_b18, &scale, m, n, &a[a_offset], lda, &
+ ierr);
+ scale = 1.f / scale;
+ }
+
+/* Row-cyclic Jacobi SVD algorithm with column pivoting */
+
+ emptsw = *n * (*n - 1) / 2;
+ notrot = 0;
+ fastr[0] = 0.f;
+
+/* A is represented in factored form A = A * diag(WORK), where diag(WORK) */
+/* is initialized to identity. WORK is updated during fast scaled */
+/* rotations. */
+
+ i__1 = *n;
+ for (q = 1; q <= i__1; ++q) {
+ work[q] = 1.f;
+/* L1868: */
+ }
+
+
+ swband = 3;
+/* [TP] SWBAND is a tuning parameter [TP]. It is meaningful and effective */
+/* if SGESVJ is used as a computational routine in the preconditioned */
+/* Jacobi SVD algorithm SGESVJ. For sweeps i=1:SWBAND the procedure */
+/* works on pivots inside a band-like region around the diagonal. */
+/* The boundaries are determined dynamically, based on the number of */
+/* pivots above a threshold. */
+
+ kbl = min(8,*n);
+/* [TP] KBL is a tuning parameter that defines the tile size in the */
+/* tiling of the p-q loops of pivot pairs. In general, an optimal */
+/* value of KBL depends on the matrix dimensions and on the */
+/* parameters of the computer's memory. */
+
+ nbl = *n / kbl;
+ if (nbl * kbl != *n) {
+ ++nbl;
+ }
+
+/* Computing 2nd power */
+ i__1 = kbl;
+ blskip = i__1 * i__1;
+/* [TP] BLKSKIP is a tuning parameter that depends on SWBAND and KBL. */
+
+ rowskip = min(5,kbl);
+/* [TP] ROWSKIP is a tuning parameter. */
+
+ lkahead = 1;
+/* [TP] LKAHEAD is a tuning parameter. */
+
+/* Quasi block transformations, using the lower (upper) triangular */
+/* structure of the input matrix. The quasi-block-cycling usually */
+/* invokes cubic convergence. Big part of this cycle is done inside */
+/* canonical subspaces of dimensions less than M. */
+
+/* Computing MAX */
+ i__1 = 64, i__2 = kbl << 2;
+ if ((lower || upper) && *n > max(i__1,i__2)) {
+/* [TP] The number of partition levels and the actual partition are */
+/* tuning parameters. */
+ n4 = *n / 4;
+ n2 = *n / 2;
+ n34 = n4 * 3;
+ if (applv) {
+ q = 0;
+ } else {
+ q = 1;
+ }
+
+ if (lower) {
+
+/* This works very well on lower triangular matrices, in particular */
+/* in the framework of the preconditioned Jacobi SVD (xGEJSV). */
+/* The idea is simple: */
+/* [+ 0 0 0] Note that Jacobi transformations of [0 0] */
+/* [+ + 0 0] [0 0] */
+/* [+ + x 0] actually work on [x 0] [x 0] */
+/* [+ + x x] [x x]. [x x] */
+
+ i__1 = *m - n34;
+ i__2 = *n - n34;
+ i__3 = *lwork - *n;
+ sgsvj0_(jobv, &i__1, &i__2, &a[n34 + 1 + (n34 + 1) * a_dim1], lda,
+ &work[n34 + 1], &sva[n34 + 1], &mvl, &v[n34 * q + 1 + (
+ n34 + 1) * v_dim1], ldv, &epsilon, &sfmin, &tol, &c__2, &
+ work[*n + 1], &i__3, &ierr);
+
+ i__1 = *m - n2;
+ i__2 = n34 - n2;
+ i__3 = *lwork - *n;
+ sgsvj0_(jobv, &i__1, &i__2, &a[n2 + 1 + (n2 + 1) * a_dim1], lda, &
+ work[n2 + 1], &sva[n2 + 1], &mvl, &v[n2 * q + 1 + (n2 + 1)
+ * v_dim1], ldv, &epsilon, &sfmin, &tol, &c__2, &work[*n
+ + 1], &i__3, &ierr);
+
+ i__1 = *m - n2;
+ i__2 = *n - n2;
+ i__3 = *lwork - *n;
+ sgsvj1_(jobv, &i__1, &i__2, &n4, &a[n2 + 1 + (n2 + 1) * a_dim1],
+ lda, &work[n2 + 1], &sva[n2 + 1], &mvl, &v[n2 * q + 1 + (
+ n2 + 1) * v_dim1], ldv, &epsilon, &sfmin, &tol, &c__1, &
+ work[*n + 1], &i__3, &ierr);
+
+ i__1 = *m - n4;
+ i__2 = n2 - n4;
+ i__3 = *lwork - *n;
+ sgsvj0_(jobv, &i__1, &i__2, &a[n4 + 1 + (n4 + 1) * a_dim1], lda, &
+ work[n4 + 1], &sva[n4 + 1], &mvl, &v[n4 * q + 1 + (n4 + 1)
+ * v_dim1], ldv, &epsilon, &sfmin, &tol, &c__1, &work[*n
+ + 1], &i__3, &ierr);
+
+ i__1 = *lwork - *n;
+ sgsvj0_(jobv, m, &n4, &a[a_offset], lda, &work[1], &sva[1], &mvl,
+ &v[v_offset], ldv, &epsilon, &sfmin, &tol, &c__1, &work[*
+ n + 1], &i__1, &ierr);
+
+ i__1 = *lwork - *n;
+ sgsvj1_(jobv, m, &n2, &n4, &a[a_offset], lda, &work[1], &sva[1], &
+ mvl, &v[v_offset], ldv, &epsilon, &sfmin, &tol, &c__1, &
+ work[*n + 1], &i__1, &ierr);
+
+
+ } else if (upper) {
+
+
+ i__1 = *lwork - *n;
+ sgsvj0_(jobv, &n4, &n4, &a[a_offset], lda, &work[1], &sva[1], &
+ mvl, &v[v_offset], ldv, &epsilon, &sfmin, &tol, &c__2, &
+ work[*n + 1], &i__1, &ierr);
+
+ i__1 = *lwork - *n;
+ sgsvj0_(jobv, &n2, &n4, &a[(n4 + 1) * a_dim1 + 1], lda, &work[n4
+ + 1], &sva[n4 + 1], &mvl, &v[n4 * q + 1 + (n4 + 1) *
+ v_dim1], ldv, &epsilon, &sfmin, &tol, &c__1, &work[*n + 1]
+, &i__1, &ierr);
+
+ i__1 = *lwork - *n;
+ sgsvj1_(jobv, &n2, &n2, &n4, &a[a_offset], lda, &work[1], &sva[1],
+ &mvl, &v[v_offset], ldv, &epsilon, &sfmin, &tol, &c__1, &
+ work[*n + 1], &i__1, &ierr);
+
+ i__1 = n2 + n4;
+ i__2 = *lwork - *n;
+ sgsvj0_(jobv, &i__1, &n4, &a[(n2 + 1) * a_dim1 + 1], lda, &work[
+ n2 + 1], &sva[n2 + 1], &mvl, &v[n2 * q + 1 + (n2 + 1) *
+ v_dim1], ldv, &epsilon, &sfmin, &tol, &c__1, &work[*n + 1]
+, &i__2, &ierr);
+ }
+
+ }
+
+/* -#- Row-cyclic pivot strategy with de Rijk's pivoting -#- */
+
+ for (i__ = 1; i__ <= 30; ++i__) {
+/* .. go go go ... */
+
+ mxaapq = 0.f;
+ mxsinj = 0.f;
+ iswrot = 0;
+
+ notrot = 0;
+ pskipped = 0;
+
+/* Each sweep is unrolled using KBL-by-KBL tiles over the pivot pairs */
+/* 1 <= p < q <= N. This is the first step toward a blocked implementation */
+/* of the rotations. New implementation, based on block transformations, */
+/* is under development. */
+
+ i__1 = nbl;
+ for (ibr = 1; ibr <= i__1; ++ibr) {
+
+ igl = (ibr - 1) * kbl + 1;
+
+/* Computing MIN */
+ i__3 = lkahead, i__4 = nbl - ibr;
+ i__2 = min(i__3,i__4);
+ for (ir1 = 0; ir1 <= i__2; ++ir1) {
+
+ igl += ir1 * kbl;
+
+/* Computing MIN */
+ i__4 = igl + kbl - 1, i__5 = *n - 1;
+ i__3 = min(i__4,i__5);
+ for (p = igl; p <= i__3; ++p) {
+
+/* .. de Rijk's pivoting */
+
+ i__4 = *n - p + 1;
+ q = isamax_(&i__4, &sva[p], &c__1) + p - 1;
+ if (p != q) {
+ sswap_(m, &a[p * a_dim1 + 1], &c__1, &a[q * a_dim1 +
+ 1], &c__1);
+ if (rsvec) {
+ sswap_(&mvl, &v[p * v_dim1 + 1], &c__1, &v[q *
+ v_dim1 + 1], &c__1);
+ }
+ temp1 = sva[p];
+ sva[p] = sva[q];
+ sva[q] = temp1;
+ temp1 = work[p];
+ work[p] = work[q];
+ work[q] = temp1;
+ }
+
+ if (ir1 == 0) {
+
+/* Column norms are periodically updated by explicit */
+/* norm computation. */
+/* Caveat: */
+/* Unfortunately, some BLAS implementations compute SNRM2(M,A(1,p),1) */
+/* as SQRT(SDOT(M,A(1,p),1,A(1,p),1)), which may cause the result to */
+/* overflow for ||A(:,p)||_2 > SQRT(overflow_threshold), and to */
+/* underflow for ||A(:,p)||_2 < SQRT(underflow_threshold). */
+/* Hence, SNRM2 cannot be trusted, not even in the case when */
+/* the true norm is far from the under(over)flow boundaries. */
+/* If properly implemented SNRM2 is available, the IF-THEN-ELSE */
+/* below should read "AAPP = SNRM2( M, A(1,p), 1 ) * WORK(p)". */
+
+ if (sva[p] < rootbig && sva[p] > rootsfmin) {
+ sva[p] = snrm2_(m, &a[p * a_dim1 + 1], &c__1) *
+ work[p];
+ } else {
+ temp1 = 0.f;
+ aapp = 0.f;
+ slassq_(m, &a[p * a_dim1 + 1], &c__1, &temp1, &
+ aapp);
+ sva[p] = temp1 * sqrt(aapp) * work[p];
+ }
+ aapp = sva[p];
+ } else {
+ aapp = sva[p];
+ }
+
+ if (aapp > 0.f) {
+
+ pskipped = 0;
+
+/* Computing MIN */
+ i__5 = igl + kbl - 1;
+ i__4 = min(i__5,*n);
+ for (q = p + 1; q <= i__4; ++q) {
+
+ aaqq = sva[q];
+
+ if (aaqq > 0.f) {
+
+ aapp0 = aapp;
+ if (aaqq >= 1.f) {
+ rotok = small * aapp <= aaqq;
+ if (aapp < big / aaqq) {
+ aapq = sdot_(m, &a[p * a_dim1 + 1], &
+ c__1, &a[q * a_dim1 + 1], &
+ c__1) * work[p] * work[q] /
+ aaqq / aapp;
+ } else {
+ scopy_(m, &a[p * a_dim1 + 1], &c__1, &
+ work[*n + 1], &c__1);
+ slascl_("G", &c__0, &c__0, &aapp, &
+ work[p], m, &c__1, &work[*n +
+ 1], lda, &ierr);
+ aapq = sdot_(m, &work[*n + 1], &c__1,
+ &a[q * a_dim1 + 1], &c__1) *
+ work[q] / aaqq;
+ }
+ } else {
+ rotok = aapp <= aaqq / small;
+ if (aapp > small / aaqq) {
+ aapq = sdot_(m, &a[p * a_dim1 + 1], &
+ c__1, &a[q * a_dim1 + 1], &
+ c__1) * work[p] * work[q] /
+ aaqq / aapp;
+ } else {
+ scopy_(m, &a[q * a_dim1 + 1], &c__1, &
+ work[*n + 1], &c__1);
+ slascl_("G", &c__0, &c__0, &aaqq, &
+ work[q], m, &c__1, &work[*n +
+ 1], lda, &ierr);
+ aapq = sdot_(m, &work[*n + 1], &c__1,
+ &a[p * a_dim1 + 1], &c__1) *
+ work[p] / aapp;
+ }
+ }
+
+/* Computing MAX */
+ r__1 = mxaapq, r__2 = dabs(aapq);
+ mxaapq = dmax(r__1,r__2);
+
+/* TO rotate or NOT to rotate, THAT is the question ... */
+
+ if (dabs(aapq) > tol) {
+
+/* .. rotate */
+/* [RTD] ROTATED = ROTATED + ONE */
+
+ if (ir1 == 0) {
+ notrot = 0;
+ pskipped = 0;
+ ++iswrot;
+ }
+
+ if (rotok) {
+
+ aqoap = aaqq / aapp;
+ apoaq = aapp / aaqq;
+ theta = (r__1 = aqoap - apoaq, dabs(
+ r__1)) * -.5f / aapq;
+
+ if (dabs(theta) > bigtheta) {
+
+ t = .5f / theta;
+ fastr[2] = t * work[p] / work[q];
+ fastr[3] = -t * work[q] / work[p];
+ srotm_(m, &a[p * a_dim1 + 1], &
+ c__1, &a[q * a_dim1 + 1],
+ &c__1, fastr);
+ if (rsvec) {
+ srotm_(&mvl, &v[p * v_dim1 + 1], &c__1, &v[q *
+ v_dim1 + 1], &c__1, fastr);
+ }
+/* Computing MAX */
+ r__1 = 0.f, r__2 = t * apoaq *
+ aapq + 1.f;
+ sva[q] = aaqq * sqrt((dmax(r__1,
+ r__2)));
+ aapp *= sqrt(1.f - t * aqoap *
+ aapq);
+/* Computing MAX */
+ r__1 = mxsinj, r__2 = dabs(t);
+ mxsinj = dmax(r__1,r__2);
+
+ } else {
+
+/* .. choose correct signum for THETA and rotate */
+
+ thsign = -r_sign(&c_b18, &aapq);
+ t = 1.f / (theta + thsign * sqrt(
+ theta * theta + 1.f));
+ cs = sqrt(1.f / (t * t + 1.f));
+ sn = t * cs;
+
+/* Computing MAX */
+ r__1 = mxsinj, r__2 = dabs(sn);
+ mxsinj = dmax(r__1,r__2);
+/* Computing MAX */
+ r__1 = 0.f, r__2 = t * apoaq *
+ aapq + 1.f;
+ sva[q] = aaqq * sqrt((dmax(r__1,
+ r__2)));
+/* Computing MAX */
+ r__1 = 0.f, r__2 = 1.f - t *
+ aqoap * aapq;
+ aapp *= sqrt((dmax(r__1,r__2)));
+
+ apoaq = work[p] / work[q];
+ aqoap = work[q] / work[p];
+ if (work[p] >= 1.f) {
+ if (work[q] >= 1.f) {
+ fastr[2] = t * apoaq;
+ fastr[3] = -t * aqoap;
+ work[p] *= cs;
+ work[q] *= cs;
+ srotm_(m, &a[p * a_dim1 + 1], &c__1, &a[q *
+ a_dim1 + 1], &c__1, fastr);
+ if (rsvec) {
+ srotm_(&mvl, &v[p * v_dim1 + 1], &c__1, &v[
+ q * v_dim1 + 1], &c__1, fastr);
+ }
+ } else {
+ r__1 = -t * aqoap;
+ saxpy_(m, &r__1, &a[q * a_dim1 + 1], &c__1, &a[
+ p * a_dim1 + 1], &c__1);
+ r__1 = cs * sn * apoaq;
+ saxpy_(m, &r__1, &a[p * a_dim1 + 1], &c__1, &a[
+ q * a_dim1 + 1], &c__1);
+ work[p] *= cs;
+ work[q] /= cs;
+ if (rsvec) {
+ r__1 = -t * aqoap;
+ saxpy_(&mvl, &r__1, &v[q * v_dim1 + 1], &
+ c__1, &v[p * v_dim1 + 1], &c__1);
+ r__1 = cs * sn * apoaq;
+ saxpy_(&mvl, &r__1, &v[p * v_dim1 + 1], &
+ c__1, &v[q * v_dim1 + 1], &c__1);
+ }
+ }
+ } else {
+ if (work[q] >= 1.f) {
+ r__1 = t * apoaq;
+ saxpy_(m, &r__1, &a[p * a_dim1 + 1], &c__1, &a[
+ q * a_dim1 + 1], &c__1);
+ r__1 = -cs * sn * aqoap;
+ saxpy_(m, &r__1, &a[q * a_dim1 + 1], &c__1, &a[
+ p * a_dim1 + 1], &c__1);
+ work[p] /= cs;
+ work[q] *= cs;
+ if (rsvec) {
+ r__1 = t * apoaq;
+ saxpy_(&mvl, &r__1, &v[p * v_dim1 + 1], &
+ c__1, &v[q * v_dim1 + 1], &c__1);
+ r__1 = -cs * sn * aqoap;
+ saxpy_(&mvl, &r__1, &v[q * v_dim1 + 1], &
+ c__1, &v[p * v_dim1 + 1], &c__1);
+ }
+ } else {
+ if (work[p] >= work[q]) {
+ r__1 = -t * aqoap;
+ saxpy_(m, &r__1, &a[q * a_dim1 + 1], &c__1,
+ &a[p * a_dim1 + 1], &c__1);
+ r__1 = cs * sn * apoaq;
+ saxpy_(m, &r__1, &a[p * a_dim1 + 1], &c__1,
+ &a[q * a_dim1 + 1], &c__1);
+ work[p] *= cs;
+ work[q] /= cs;
+ if (rsvec) {
+ r__1 = -t * aqoap;
+ saxpy_(&mvl, &r__1, &v[q * v_dim1 + 1],
+ &c__1, &v[p * v_dim1 + 1], &
+ c__1);
+ r__1 = cs * sn * apoaq;
+ saxpy_(&mvl, &r__1, &v[p * v_dim1 + 1],
+ &c__1, &v[q * v_dim1 + 1], &
+ c__1);
+ }
+ } else {
+ r__1 = t * apoaq;
+ saxpy_(m, &r__1, &a[p * a_dim1 + 1], &c__1,
+ &a[q * a_dim1 + 1], &c__1);
+ r__1 = -cs * sn * aqoap;
+ saxpy_(m, &r__1, &a[q * a_dim1 + 1], &c__1,
+ &a[p * a_dim1 + 1], &c__1);
+ work[p] /= cs;
+ work[q] *= cs;
+ if (rsvec) {
+ r__1 = t * apoaq;
+ saxpy_(&mvl, &r__1, &v[p * v_dim1 + 1],
+ &c__1, &v[q * v_dim1 + 1], &
+ c__1);
+ r__1 = -cs * sn * aqoap;
+ saxpy_(&mvl, &r__1, &v[q * v_dim1 + 1],
+ &c__1, &v[p * v_dim1 + 1], &
+ c__1);
+ }
+ }
+ }
+ }
+ }
+
+ } else {
+/* .. have to use modified Gram-Schmidt like transformation */
+ scopy_(m, &a[p * a_dim1 + 1], &c__1, &
+ work[*n + 1], &c__1);
+ slascl_("G", &c__0, &c__0, &aapp, &
+ c_b18, m, &c__1, &work[*n + 1]
+, lda, &ierr);
+ slascl_("G", &c__0, &c__0, &aaqq, &
+ c_b18, m, &c__1, &a[q *
+ a_dim1 + 1], lda, &ierr);
+ temp1 = -aapq * work[p] / work[q];
+ saxpy_(m, &temp1, &work[*n + 1], &
+ c__1, &a[q * a_dim1 + 1], &
+ c__1);
+ slascl_("G", &c__0, &c__0, &c_b18, &
+ aaqq, m, &c__1, &a[q * a_dim1
+ + 1], lda, &ierr);
+/* Computing MAX */
+ r__1 = 0.f, r__2 = 1.f - aapq * aapq;
+ sva[q] = aaqq * sqrt((dmax(r__1,r__2))
+ );
+ mxsinj = dmax(mxsinj,sfmin);
+ }
+/* END IF ROTOK THEN ... ELSE */
+
+/* In the case of cancellation in updating SVA(q), SVA(p) */
+/* recompute SVA(q), SVA(p). */
+
+/* Computing 2nd power */
+ r__1 = sva[q] / aaqq;
+ if (r__1 * r__1 <= rooteps) {
+ if (aaqq < rootbig && aaqq >
+ rootsfmin) {
+ sva[q] = snrm2_(m, &a[q * a_dim1
+ + 1], &c__1) * work[q];
+ } else {
+ t = 0.f;
+ aaqq = 0.f;
+ slassq_(m, &a[q * a_dim1 + 1], &
+ c__1, &t, &aaqq);
+ sva[q] = t * sqrt(aaqq) * work[q];
+ }
+ }
+ if (aapp / aapp0 <= rooteps) {
+ if (aapp < rootbig && aapp >
+ rootsfmin) {
+ aapp = snrm2_(m, &a[p * a_dim1 +
+ 1], &c__1) * work[p];
+ } else {
+ t = 0.f;
+ aapp = 0.f;
+ slassq_(m, &a[p * a_dim1 + 1], &
+ c__1, &t, &aapp);
+ aapp = t * sqrt(aapp) * work[p];
+ }
+ sva[p] = aapp;
+ }
+
+ } else {
+/* A(:,p) and A(:,q) already numerically orthogonal */
+ if (ir1 == 0) {
+ ++notrot;
+ }
+/* [RTD] SKIPPED = SKIPPED + 1 */
+ ++pskipped;
+ }
+ } else {
+/* A(:,q) is zero column */
+ if (ir1 == 0) {
+ ++notrot;
+ }
+ ++pskipped;
+ }
+
+ if (i__ <= swband && pskipped > rowskip) {
+ if (ir1 == 0) {
+ aapp = -aapp;
+ }
+ notrot = 0;
+ goto L2103;
+ }
+
+/* L2002: */
+ }
+/* END q-LOOP */
+
+L2103:
+/* bailed out of q-loop */
+
+ sva[p] = aapp;
+
+ } else {
+ sva[p] = aapp;
+ if (ir1 == 0 && aapp == 0.f) {
+/* Computing MIN */
+ i__4 = igl + kbl - 1;
+ notrot = notrot + min(i__4,*n) - p;
+ }
+ }
+
+/* L2001: */
+ }
+/* end of the p-loop */
+/* end of doing the block ( ibr, ibr ) */
+/* L1002: */
+ }
+/* end of ir1-loop */
+
+/* ... go to the off diagonal blocks */
+
+ igl = (ibr - 1) * kbl + 1;
+
+ i__2 = nbl;
+ for (jbc = ibr + 1; jbc <= i__2; ++jbc) {
+
+ jgl = (jbc - 1) * kbl + 1;
+
+/* doing the block at ( ibr, jbc ) */
+
+ ijblsk = 0;
+/* Computing MIN */
+ i__4 = igl + kbl - 1;
+ i__3 = min(i__4,*n);
+ for (p = igl; p <= i__3; ++p) {
+
+ aapp = sva[p];
+ if (aapp > 0.f) {
+
+ pskipped = 0;
+
+/* Computing MIN */
+ i__5 = jgl + kbl - 1;
+ i__4 = min(i__5,*n);
+ for (q = jgl; q <= i__4; ++q) {
+
+ aaqq = sva[q];
+ if (aaqq > 0.f) {
+ aapp0 = aapp;
+
+/* -#- M x 2 Jacobi SVD -#- */
+
+/* Safe Gram matrix computation */
+
+ if (aaqq >= 1.f) {
+ if (aapp >= aaqq) {
+ rotok = small * aapp <= aaqq;
+ } else {
+ rotok = small * aaqq <= aapp;
+ }
+ if (aapp < big / aaqq) {
+ aapq = sdot_(m, &a[p * a_dim1 + 1], &
+ c__1, &a[q * a_dim1 + 1], &
+ c__1) * work[p] * work[q] /
+ aaqq / aapp;
+ } else {
+ scopy_(m, &a[p * a_dim1 + 1], &c__1, &
+ work[*n + 1], &c__1);
+ slascl_("G", &c__0, &c__0, &aapp, &
+ work[p], m, &c__1, &work[*n +
+ 1], lda, &ierr);
+ aapq = sdot_(m, &work[*n + 1], &c__1,
+ &a[q * a_dim1 + 1], &c__1) *
+ work[q] / aaqq;
+ }
+ } else {
+ if (aapp >= aaqq) {
+ rotok = aapp <= aaqq / small;
+ } else {
+ rotok = aaqq <= aapp / small;
+ }
+ if (aapp > small / aaqq) {
+ aapq = sdot_(m, &a[p * a_dim1 + 1], &
+ c__1, &a[q * a_dim1 + 1], &
+ c__1) * work[p] * work[q] /
+ aaqq / aapp;
+ } else {
+ scopy_(m, &a[q * a_dim1 + 1], &c__1, &
+ work[*n + 1], &c__1);
+ slascl_("G", &c__0, &c__0, &aaqq, &
+ work[q], m, &c__1, &work[*n +
+ 1], lda, &ierr);
+ aapq = sdot_(m, &work[*n + 1], &c__1,
+ &a[p * a_dim1 + 1], &c__1) *
+ work[p] / aapp;
+ }
+ }
+
+/* Computing MAX */
+ r__1 = mxaapq, r__2 = dabs(aapq);
+ mxaapq = dmax(r__1,r__2);
+
+/* TO rotate or NOT to rotate, THAT is the question ... */
+
+ if (dabs(aapq) > tol) {
+ notrot = 0;
+/* [RTD] ROTATED = ROTATED + 1 */
+ pskipped = 0;
+ ++iswrot;
+
+ if (rotok) {
+
+ aqoap = aaqq / aapp;
+ apoaq = aapp / aaqq;
+ theta = (r__1 = aqoap - apoaq, dabs(
+ r__1)) * -.5f / aapq;
+ if (aaqq > aapp0) {
+ theta = -theta;
+ }
+
+ if (dabs(theta) > bigtheta) {
+ t = .5f / theta;
+ fastr[2] = t * work[p] / work[q];
+ fastr[3] = -t * work[q] / work[p];
+ srotm_(m, &a[p * a_dim1 + 1], &
+ c__1, &a[q * a_dim1 + 1],
+ &c__1, fastr);
+ if (rsvec) {
+ srotm_(&mvl, &v[p * v_dim1 + 1], &c__1, &v[q *
+ v_dim1 + 1], &c__1, fastr);
+ }
+/* Computing MAX */
+ r__1 = 0.f, r__2 = t * apoaq *
+ aapq + 1.f;
+ sva[q] = aaqq * sqrt((dmax(r__1,
+ r__2)));
+/* Computing MAX */
+ r__1 = 0.f, r__2 = 1.f - t *
+ aqoap * aapq;
+ aapp *= sqrt((dmax(r__1,r__2)));
+/* Computing MAX */
+ r__1 = mxsinj, r__2 = dabs(t);
+ mxsinj = dmax(r__1,r__2);
+ } else {
+
+/* .. choose correct signum for THETA and rotate */
+
+ thsign = -r_sign(&c_b18, &aapq);
+ if (aaqq > aapp0) {
+ thsign = -thsign;
+ }
+ t = 1.f / (theta + thsign * sqrt(
+ theta * theta + 1.f));
+ cs = sqrt(1.f / (t * t + 1.f));
+ sn = t * cs;
+/* Computing MAX */
+ r__1 = mxsinj, r__2 = dabs(sn);
+ mxsinj = dmax(r__1,r__2);
+/* Computing MAX */
+ r__1 = 0.f, r__2 = t * apoaq *
+ aapq + 1.f;
+ sva[q] = aaqq * sqrt((dmax(r__1,
+ r__2)));
+ aapp *= sqrt(1.f - t * aqoap *
+ aapq);
+
+ apoaq = work[p] / work[q];
+ aqoap = work[q] / work[p];
+ if (work[p] >= 1.f) {
+
+ if (work[q] >= 1.f) {
+ fastr[2] = t * apoaq;
+ fastr[3] = -t * aqoap;
+ work[p] *= cs;
+ work[q] *= cs;
+ srotm_(m, &a[p * a_dim1 + 1], &c__1, &a[q *
+ a_dim1 + 1], &c__1, fastr);
+ if (rsvec) {
+ srotm_(&mvl, &v[p * v_dim1 + 1], &c__1, &v[
+ q * v_dim1 + 1], &c__1, fastr);
+ }
+ } else {
+ r__1 = -t * aqoap;
+ saxpy_(m, &r__1, &a[q * a_dim1 + 1], &c__1, &a[
+ p * a_dim1 + 1], &c__1);
+ r__1 = cs * sn * apoaq;
+ saxpy_(m, &r__1, &a[p * a_dim1 + 1], &c__1, &a[
+ q * a_dim1 + 1], &c__1);
+ if (rsvec) {
+ r__1 = -t * aqoap;
+ saxpy_(&mvl, &r__1, &v[q * v_dim1 + 1], &
+ c__1, &v[p * v_dim1 + 1], &c__1);
+ r__1 = cs * sn * apoaq;
+ saxpy_(&mvl, &r__1, &v[p * v_dim1 + 1], &
+ c__1, &v[q * v_dim1 + 1], &c__1);
+ }
+ work[p] *= cs;
+ work[q] /= cs;
+ }
+ } else {
+ if (work[q] >= 1.f) {
+ r__1 = t * apoaq;
+ saxpy_(m, &r__1, &a[p * a_dim1 + 1], &c__1, &a[
+ q * a_dim1 + 1], &c__1);
+ r__1 = -cs * sn * aqoap;
+ saxpy_(m, &r__1, &a[q * a_dim1 + 1], &c__1, &a[
+ p * a_dim1 + 1], &c__1);
+ if (rsvec) {
+ r__1 = t * apoaq;
+ saxpy_(&mvl, &r__1, &v[p * v_dim1 + 1], &
+ c__1, &v[q * v_dim1 + 1], &c__1);
+ r__1 = -cs * sn * aqoap;
+ saxpy_(&mvl, &r__1, &v[q * v_dim1 + 1], &
+ c__1, &v[p * v_dim1 + 1], &c__1);
+ }
+ work[p] /= cs;
+ work[q] *= cs;
+ } else {
+ if (work[p] >= work[q]) {
+ r__1 = -t * aqoap;
+ saxpy_(m, &r__1, &a[q * a_dim1 + 1], &c__1,
+ &a[p * a_dim1 + 1], &c__1);
+ r__1 = cs * sn * apoaq;
+ saxpy_(m, &r__1, &a[p * a_dim1 + 1], &c__1,
+ &a[q * a_dim1 + 1], &c__1);
+ work[p] *= cs;
+ work[q] /= cs;
+ if (rsvec) {
+ r__1 = -t * aqoap;
+ saxpy_(&mvl, &r__1, &v[q * v_dim1 + 1],
+ &c__1, &v[p * v_dim1 + 1], &
+ c__1);
+ r__1 = cs * sn * apoaq;
+ saxpy_(&mvl, &r__1, &v[p * v_dim1 + 1],
+ &c__1, &v[q * v_dim1 + 1], &
+ c__1);
+ }
+ } else {
+ r__1 = t * apoaq;
+ saxpy_(m, &r__1, &a[p * a_dim1 + 1], &c__1,
+ &a[q * a_dim1 + 1], &c__1);
+ r__1 = -cs * sn * aqoap;
+ saxpy_(m, &r__1, &a[q * a_dim1 + 1], &c__1,
+ &a[p * a_dim1 + 1], &c__1);
+ work[p] /= cs;
+ work[q] *= cs;
+ if (rsvec) {
+ r__1 = t * apoaq;
+ saxpy_(&mvl, &r__1, &v[p * v_dim1 + 1],
+ &c__1, &v[q * v_dim1 + 1], &
+ c__1);
+ r__1 = -cs * sn * aqoap;
+ saxpy_(&mvl, &r__1, &v[q * v_dim1 + 1],
+ &c__1, &v[p * v_dim1 + 1], &
+ c__1);
+ }
+ }
+ }
+ }
+ }
+
+ } else {
+ if (aapp > aaqq) {
+ scopy_(m, &a[p * a_dim1 + 1], &
+ c__1, &work[*n + 1], &
+ c__1);
+ slascl_("G", &c__0, &c__0, &aapp,
+ &c_b18, m, &c__1, &work[*
+ n + 1], lda, &ierr);
+ slascl_("G", &c__0, &c__0, &aaqq,
+ &c_b18, m, &c__1, &a[q *
+ a_dim1 + 1], lda, &ierr);
+ temp1 = -aapq * work[p] / work[q];
+ saxpy_(m, &temp1, &work[*n + 1], &
+ c__1, &a[q * a_dim1 + 1],
+ &c__1);
+ slascl_("G", &c__0, &c__0, &c_b18,
+ &aaqq, m, &c__1, &a[q *
+ a_dim1 + 1], lda, &ierr);
+/* Computing MAX */
+ r__1 = 0.f, r__2 = 1.f - aapq *
+ aapq;
+ sva[q] = aaqq * sqrt((dmax(r__1,
+ r__2)));
+ mxsinj = dmax(mxsinj,sfmin);
+ } else {
+ scopy_(m, &a[q * a_dim1 + 1], &
+ c__1, &work[*n + 1], &
+ c__1);
+ slascl_("G", &c__0, &c__0, &aaqq,
+ &c_b18, m, &c__1, &work[*
+ n + 1], lda, &ierr);
+ slascl_("G", &c__0, &c__0, &aapp,
+ &c_b18, m, &c__1, &a[p *
+ a_dim1 + 1], lda, &ierr);
+ temp1 = -aapq * work[q] / work[p];
+ saxpy_(m, &temp1, &work[*n + 1], &
+ c__1, &a[p * a_dim1 + 1],
+ &c__1);
+ slascl_("G", &c__0, &c__0, &c_b18,
+ &aapp, m, &c__1, &a[p *
+ a_dim1 + 1], lda, &ierr);
+/* Computing MAX */
+ r__1 = 0.f, r__2 = 1.f - aapq *
+ aapq;
+ sva[p] = aapp * sqrt((dmax(r__1,
+ r__2)));
+ mxsinj = dmax(mxsinj,sfmin);
+ }
+ }
+/* END IF ROTOK THEN ... ELSE */
+
+/* In the case of cancellation in updating SVA(q) */
+/* .. recompute SVA(q) */
+/* Computing 2nd power */
+ r__1 = sva[q] / aaqq;
+ if (r__1 * r__1 <= rooteps) {
+ if (aaqq < rootbig && aaqq >
+ rootsfmin) {
+ sva[q] = snrm2_(m, &a[q * a_dim1
+ + 1], &c__1) * work[q];
+ } else {
+ t = 0.f;
+ aaqq = 0.f;
+ slassq_(m, &a[q * a_dim1 + 1], &
+ c__1, &t, &aaqq);
+ sva[q] = t * sqrt(aaqq) * work[q];
+ }
+ }
+/* Computing 2nd power */
+ r__1 = aapp / aapp0;
+ if (r__1 * r__1 <= rooteps) {
+ if (aapp < rootbig && aapp >
+ rootsfmin) {
+ aapp = snrm2_(m, &a[p * a_dim1 +
+ 1], &c__1) * work[p];
+ } else {
+ t = 0.f;
+ aapp = 0.f;
+ slassq_(m, &a[p * a_dim1 + 1], &
+ c__1, &t, &aapp);
+ aapp = t * sqrt(aapp) * work[p];
+ }
+ sva[p] = aapp;
+ }
+/* end of OK rotation */
+ } else {
+ ++notrot;
+/* [RTD] SKIPPED = SKIPPED + 1 */
+ ++pskipped;
+ ++ijblsk;
+ }
+ } else {
+ ++notrot;
+ ++pskipped;
+ ++ijblsk;
+ }
+
+ if (i__ <= swband && ijblsk >= blskip) {
+ sva[p] = aapp;
+ notrot = 0;
+ goto L2011;
+ }
+ if (i__ <= swband && pskipped > rowskip) {
+ aapp = -aapp;
+ notrot = 0;
+ goto L2203;
+ }
+
+/* L2200: */
+ }
+/* end of the q-loop */
+L2203:
+
+ sva[p] = aapp;
+
+ } else {
+
+ if (aapp == 0.f) {
+/* Computing MIN */
+ i__4 = jgl + kbl - 1;
+ notrot = notrot + min(i__4,*n) - jgl + 1;
+ }
+ if (aapp < 0.f) {
+ notrot = 0;
+ }
+
+ }
+
+/* L2100: */
+ }
+/* end of the p-loop */
+/* L2010: */
+ }
+/* end of the jbc-loop */
+L2011:
+/* 2011 bailed out of the jbc-loop */
+/* Computing MIN */
+ i__3 = igl + kbl - 1;
+ i__2 = min(i__3,*n);
+ for (p = igl; p <= i__2; ++p) {
+ sva[p] = (r__1 = sva[p], dabs(r__1));
+/* L2012: */
+ }
+/* ** */
+/* L2000: */
+ }
+/* 2000 :: end of the ibr-loop */
+
+/* .. update SVA(N) */
+ if (sva[*n] < rootbig && sva[*n] > rootsfmin) {
+ sva[*n] = snrm2_(m, &a[*n * a_dim1 + 1], &c__1) * work[*n];
+ } else {
+ t = 0.f;
+ aapp = 0.f;
+ slassq_(m, &a[*n * a_dim1 + 1], &c__1, &t, &aapp);
+ sva[*n] = t * sqrt(aapp) * work[*n];
+ }
+
+/* Additional steering devices */
+
+ if (i__ < swband && (mxaapq <= roottol || iswrot <= *n)) {
+ swband = i__;
+ }
+
+ if (i__ > swband + 1 && mxaapq < sqrt((real) (*n)) * tol && (real) (*
+ n) * mxaapq * mxsinj < tol) {
+ goto L1994;
+ }
+
+ if (notrot >= emptsw) {
+ goto L1994;
+ }
+
+/* L1993: */
+ }
+/* end i=1:NSWEEP loop */
+
+/* #:( Reaching this point means that the procedure has not converged. */
+ *info = 29;
+ goto L1995;
+
+L1994:
+/* #:) Reaching this point means numerical convergence after the i-th */
+/* sweep. */
+
+ *info = 0;
+/* #:) INFO = 0 confirms successful iterations. */
+L1995:
+
+/* Sort the singular values and find how many are above */
+/* the underflow threshold. */
+
+ n2 = 0;
+ n4 = 0;
+ i__1 = *n - 1;
+ for (p = 1; p <= i__1; ++p) {
+ i__2 = *n - p + 1;
+ q = isamax_(&i__2, &sva[p], &c__1) + p - 1;
+ if (p != q) {
+ temp1 = sva[p];
+ sva[p] = sva[q];
+ sva[q] = temp1;
+ temp1 = work[p];
+ work[p] = work[q];
+ work[q] = temp1;
+ sswap_(m, &a[p * a_dim1 + 1], &c__1, &a[q * a_dim1 + 1], &c__1);
+ if (rsvec) {
+ sswap_(&mvl, &v[p * v_dim1 + 1], &c__1, &v[q * v_dim1 + 1], &
+ c__1);
+ }
+ }
+ if (sva[p] != 0.f) {
+ ++n4;
+ if (sva[p] * scale > sfmin) {
+ ++n2;
+ }
+ }
+/* L5991: */
+ }
+ if (sva[*n] != 0.f) {
+ ++n4;
+ if (sva[*n] * scale > sfmin) {
+ ++n2;
+ }
+ }
+
+/* Normalize the left singular vectors. */
+
+ if (lsvec || uctol) {
+ i__1 = n2;
+ for (p = 1; p <= i__1; ++p) {
+ r__1 = work[p] / sva[p];
+ sscal_(m, &r__1, &a[p * a_dim1 + 1], &c__1);
+/* L1998: */
+ }
+ }
+
+/* Scale the product of Jacobi rotations (assemble the fast rotations). */
+
+ if (rsvec) {
+ if (applv) {
+ i__1 = *n;
+ for (p = 1; p <= i__1; ++p) {
+ sscal_(&mvl, &work[p], &v[p * v_dim1 + 1], &c__1);
+/* L2398: */
+ }
+ } else {
+ i__1 = *n;
+ for (p = 1; p <= i__1; ++p) {
+ temp1 = 1.f / snrm2_(&mvl, &v[p * v_dim1 + 1], &c__1);
+ sscal_(&mvl, &temp1, &v[p * v_dim1 + 1], &c__1);
+/* L2399: */
+ }
+ }
+ }
+
+/* Undo scaling, if necessary (and possible). */
+ if (scale > 1.f && sva[1] < big / scale || scale < 1.f && sva[n2] > sfmin
+ / scale) {
+ i__1 = *n;
+ for (p = 1; p <= i__1; ++p) {
+ sva[p] = scale * sva[p];
+/* L2400: */
+ }
+ scale = 1.f;
+ }
+
+ work[1] = scale;
+/* The singular values of A are SCALE*SVA(1:N). If SCALE.NE.ONE */
+/* then some of the singular values may overflow or underflow and */
+/* the spectrum is given in this factored representation. */
+
+ work[2] = (real) n4;
+/* N4 is the number of computed nonzero singular values of A. */
+
+ work[3] = (real) n2;
+/* N2 is the number of singular values of A greater than SFMIN. */
+/* If N2<N, SVA(N2:N) contains ZEROS and/or denormalized numbers */
+/* that may carry some information. */
+
+ work[4] = (real) i__;
+/* i is the index of the last sweep before declaring convergence. */
+
+ work[5] = mxaapq;
+/* MXAAPQ is the largest absolute value of scaled pivots in the */
+/* last sweep */
+
+ work[6] = mxsinj;
+/* MXSINJ is the largest absolute value of the sines of Jacobi angles */
+/* in the last sweep */
+
+ return 0;
+/* .. */
+/* .. END OF SGESVJ */
+/* .. */
+} /* sgesvj_ */