/* dgesdd.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 "clapack.h" /* Table of constant values */ static integer c__1 = 1; static integer c_n1 = -1; static integer c__0 = 0; static doublereal c_b227 = 0.; static doublereal c_b248 = 1.; /* Subroutine */ int dgesdd_(char *jobz, integer *m, integer *n, doublereal * a, integer *lda, doublereal *s, doublereal *u, integer *ldu, doublereal *vt, integer *ldvt, doublereal *work, integer *lwork, integer *iwork, integer *info) { /* System generated locals */ integer a_dim1, a_offset, u_dim1, u_offset, vt_dim1, vt_offset, i__1, i__2, i__3; /* Builtin functions */ double sqrt(doublereal); /* Local variables */ integer i__, ie, il, ir, iu, blk; doublereal dum[1], eps; integer ivt, iscl; doublereal anrm; integer idum[1], ierr, itau; extern /* Subroutine */ int dgemm_(char *, char *, integer *, integer *, integer *, doublereal *, doublereal *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *); extern logical lsame_(char *, char *); integer chunk, minmn, wrkbl, itaup, itauq, mnthr; logical wntqa; integer nwork; logical wntqn, wntqo, wntqs; extern /* Subroutine */ int dbdsdc_(char *, char *, integer *, doublereal *, doublereal *, doublereal *, integer *, doublereal *, integer *, doublereal *, integer *, doublereal *, integer *, integer *), dgebrd_(integer *, integer *, doublereal *, integer *, doublereal *, doublereal *, doublereal *, doublereal *, doublereal *, integer *, integer *); extern doublereal dlamch_(char *), dlange_(char *, integer *, integer *, doublereal *, integer *, doublereal *); integer bdspac; extern /* Subroutine */ int dgelqf_(integer *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *, integer *), dlascl_(char *, integer *, integer *, doublereal *, doublereal *, integer *, integer *, doublereal *, integer *, integer *), dgeqrf_(integer *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *, integer *), dlacpy_(char *, integer *, integer *, doublereal *, integer *, doublereal *, integer *), dlaset_(char *, integer *, integer *, doublereal *, doublereal *, doublereal *, integer *), xerbla_(char *, integer *), dorgbr_(char *, integer *, integer *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *); doublereal bignum; extern /* Subroutine */ int dormbr_(char *, char *, char *, integer *, integer *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *, doublereal *, integer *, integer *), dorglq_(integer *, integer *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *, integer *), dorgqr_(integer *, integer *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *, integer *); integer ldwrkl, ldwrkr, minwrk, ldwrku, maxwrk, ldwkvt; doublereal smlnum; logical wntqas, lquery; /* -- LAPACK driver routine (version 3.2.1) -- */ /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */ /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */ /* March 2009 */ /* .. Scalar Arguments .. */ /* .. */ /* .. Array Arguments .. */ /* .. */ /* Purpose */ /* ======= */ /* DGESDD computes the singular value decomposition (SVD) of a real */ /* M-by-N matrix A, optionally computing the left and right singular */ /* vectors. If singular vectors are desired, it uses a */ /* divide-and-conquer algorithm. */ /* The SVD is written */ /* A = U * SIGMA * transpose(V) */ /* where SIGMA is an M-by-N matrix which is zero except for its */ /* min(m,n) diagonal elements, U is an M-by-M orthogonal matrix, and */ /* V is an N-by-N orthogonal matrix. The diagonal elements of SIGMA */ /* are the singular values of A; they are real and non-negative, and */ /* are returned in descending order. The first min(m,n) columns of */ /* U and V are the left and right singular vectors of A. */ /* Note that the routine returns VT = V**T, not V. */ /* The divide and conquer algorithm makes very mild assumptions about */ /* floating point arithmetic. It will work on machines with a guard */ /* digit in add/subtract, or on those binary machines without guard */ /* digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or */ /* Cray-2. It could conceivably fail on hexadecimal or decimal machines */ /* without guard digits, but we know of none. */ /* Arguments */ /* ========= */ /* JOBZ (input) CHARACTER*1 */ /* Specifies options for computing all or part of the matrix U: */ /* = 'A': all M columns of U and all N rows of V**T are */ /* returned in the arrays U and VT; */ /* = 'S': the first min(M,N) columns of U and the first */ /* min(M,N) rows of V**T are returned in the arrays U */ /* and VT; */ /* = 'O': If M >= N, the first N columns of U are overwritten */ /* on the array A and all rows of V**T are returned in */ /* the array VT; */ /* otherwise, all columns of U are returned in the */ /* array U and the first M rows of V**T are overwritten */ /* in the array A; */ /* = 'N': no columns of U or rows of V**T are computed. */ /* 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. N >= 0. */ /* A (input/output) DOUBLE PRECISION array, dimension (LDA,N) */ /* On entry, the M-by-N matrix A. */ /* On exit, */ /* if JOBZ = 'O', A is overwritten with the first N columns */ /* of U (the left singular vectors, stored */ /* columnwise) if M >= N; */ /* A is overwritten with the first M rows */ /* of V**T (the right singular vectors, stored */ /* rowwise) otherwise. */ /* if JOBZ .ne. 'O', the contents of A are destroyed. */ /* LDA (input) INTEGER */ /* The leading dimension of the array A. LDA >= max(1,M). */ /* S (output) DOUBLE PRECISION array, dimension (min(M,N)) */ /* The singular values of A, sorted so that S(i) >= S(i+1). */ /* U (output) DOUBLE PRECISION array, dimension (LDU,UCOL) */ /* UCOL = M if JOBZ = 'A' or JOBZ = 'O' and M < N; */ /* UCOL = min(M,N) if JOBZ = 'S'. */ /* If JOBZ = 'A' or JOBZ = 'O' and M < N, U contains the M-by-M */ /* orthogonal matrix U; */ /* if JOBZ = 'S', U contains the first min(M,N) columns of U */ /* (the left singular vectors, stored columnwise); */ /* if JOBZ = 'O' and M >= N, or JOBZ = 'N', U is not referenced. */ /* LDU (input) INTEGER */ /* The leading dimension of the array U. LDU >= 1; if */ /* JOBZ = 'S' or 'A' or JOBZ = 'O' and M < N, LDU >= M. */ /* VT (output) DOUBLE PRECISION array, dimension (LDVT,N) */ /* If JOBZ = 'A' or JOBZ = 'O' and M >= N, VT contains the */ /* N-by-N orthogonal matrix V**T; */ /* if JOBZ = 'S', VT contains the first min(M,N) rows of */ /* V**T (the right singular vectors, stored rowwise); */ /* if JOBZ = 'O' and M < N, or JOBZ = 'N', VT is not referenced. */ /* LDVT (input) INTEGER */ /* The leading dimension of the array VT. LDVT >= 1; if */ /* JOBZ = 'A' or JOBZ = 'O' and M >= N, LDVT >= N; */ /* if JOBZ = 'S', LDVT >= min(M,N). */ /* WORK (workspace/output) DOUBLE PRECISION array, dimension (MAX(1,LWORK)) */ /* On exit, if INFO = 0, WORK(1) returns the optimal LWORK; */ /* LWORK (input) INTEGER */ /* The dimension of the array WORK. LWORK >= 1. */ /* If JOBZ = 'N', */ /* LWORK >= 3*min(M,N) + max(max(M,N),7*min(M,N)). */ /* If JOBZ = 'O', */ /* LWORK >= 3*min(M,N) + */ /* max(max(M,N),5*min(M,N)*min(M,N)+4*min(M,N)). */ /* If JOBZ = 'S' or 'A' */ /* LWORK >= 3*min(M,N) + */ /* max(max(M,N),4*min(M,N)*min(M,N)+4*min(M,N)). */ /* For good performance, LWORK should generally be larger. */ /* If LWORK = -1 but other input arguments are legal, WORK(1) */ /* returns the optimal LWORK. */ /* IWORK (workspace) INTEGER array, dimension (8*min(M,N)) */ /* INFO (output) INTEGER */ /* = 0: successful exit. */ /* < 0: if INFO = -i, the i-th argument had an illegal value. */ /* > 0: DBDSDC did not converge, updating process failed. */ /* Further Details */ /* =============== */ /* Based on contributions by */ /* Ming Gu and Huan Ren, Computer Science Division, University of */ /* California at Berkeley, USA */ /* ===================================================================== */ /* .. Parameters .. */ /* .. */ /* .. Local Scalars .. */ /* .. */ /* .. Local Arrays .. */ /* .. */ /* .. External Subroutines .. */ /* .. */ /* .. External Functions .. */ /* .. */ /* .. Intrinsic Functions .. */ /* .. */ /* .. Executable Statements .. */ /* Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --s; u_dim1 = *ldu; u_offset = 1 + u_dim1; u -= u_offset; vt_dim1 = *ldvt; vt_offset = 1 + vt_dim1; vt -= vt_offset; --work; --iwork; /* Function Body */ *info = 0; minmn = min(*m,*n); wntqa = lsame_(jobz, "A"); wntqs = lsame_(jobz, "S"); wntqas = wntqa || wntqs; wntqo = lsame_(jobz, "O"); wntqn = lsame_(jobz, "N"); lquery = *lwork == -1; if (! (wntqa || wntqs || wntqo || wntqn)) { *info = -1; } else if (*m < 0) { *info = -2; } else if (*n < 0) { *info = -3; } else if (*lda < max(1,*m)) { *info = -5; } else if (*ldu < 1 || wntqas && *ldu < *m || wntqo && *m < *n && *ldu < * m) { *info = -8; } else if (*ldvt < 1 || wntqa && *ldvt < *n || wntqs && *ldvt < minmn || wntqo && *m >= *n && *ldvt < *n) { *info = -10; } /* Compute workspace */ /* (Note: Comments in the code beginning "Workspace:" describe the */ /* minimal amount of workspace needed at that point in the code, */ /* as well as the preferred amount for good performance. */ /* NB refers to the optimal block size for the immediately */ /* following subroutine, as returned by ILAENV.) */ if (*info == 0) { minwrk = 1; maxwrk = 1; if (*m >= *n && minmn > 0) { /* Compute space needed for DBDSDC */ mnthr = (integer) (minmn * 11. / 6.); if (wntqn) { bdspac = *n * 7; } else { bdspac = *n * 3 * *n + (*n << 2); } if (*m >= mnthr) { if (wntqn) { /* Path 1 (M much larger than N, JOBZ='N') */ wrkbl = *n + *n * ilaenv_(&c__1, "DGEQRF", " ", m, n, & c_n1, &c_n1); /* Computing MAX */ i__1 = wrkbl, i__2 = *n * 3 + (*n << 1) * ilaenv_(&c__1, "DGEBRD", " ", n, n, &c_n1, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = bdspac + *n; maxwrk = max(i__1,i__2); minwrk = bdspac + *n; } else if (wntqo) { /* Path 2 (M much larger than N, JOBZ='O') */ wrkbl = *n + *n * ilaenv_(&c__1, "DGEQRF", " ", m, n, & c_n1, &c_n1); /* Computing MAX */ i__1 = wrkbl, i__2 = *n + *n * ilaenv_(&c__1, "DORGQR", " ", m, n, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *n * 3 + (*n << 1) * ilaenv_(&c__1, "DGEBRD", " ", n, n, &c_n1, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *n * 3 + *n * ilaenv_(&c__1, "DORMBR" , "QLN", n, n, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *n * 3 + *n * ilaenv_(&c__1, "DORMBR" , "PRT", n, n, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = bdspac + *n * 3; wrkbl = max(i__1,i__2); maxwrk = wrkbl + (*n << 1) * *n; minwrk = bdspac + (*n << 1) * *n + *n * 3; } else if (wntqs) { /* Path 3 (M much larger than N, JOBZ='S') */ wrkbl = *n + *n * ilaenv_(&c__1, "DGEQRF", " ", m, n, & c_n1, &c_n1); /* Computing MAX */ i__1 = wrkbl, i__2 = *n + *n * ilaenv_(&c__1, "DORGQR", " ", m, n, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *n * 3 + (*n << 1) * ilaenv_(&c__1, "DGEBRD", " ", n, n, &c_n1, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *n * 3 + *n * ilaenv_(&c__1, "DORMBR" , "QLN", n, n, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *n * 3 + *n * ilaenv_(&c__1, "DORMBR" , "PRT", n, n, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = bdspac + *n * 3; wrkbl = max(i__1,i__2); maxwrk = wrkbl + *n * *n; minwrk = bdspac + *n * *n + *n * 3; } else if (wntqa) { /* Path 4 (M much larger than N, JOBZ='A') */ wrkbl = *n + *n * ilaenv_(&c__1, "DGEQRF", " ", m, n, & c_n1, &c_n1); /* Computing MAX */ i__1 = wrkbl, i__2 = *n + *m * ilaenv_(&c__1, "DORGQR", " ", m, m, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *n * 3 + (*n << 1) * ilaenv_(&c__1, "DGEBRD", " ", n, n, &c_n1, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *n * 3 + *n * ilaenv_(&c__1, "DORMBR" , "QLN", n, n, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *n * 3 + *n * ilaenv_(&c__1, "DORMBR" , "PRT", n, n, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = bdspac + *n * 3; wrkbl = max(i__1,i__2); maxwrk = wrkbl + *n * *n; minwrk = bdspac + *n * *n + *n * 3; } } else { /* Path 5 (M at least N, but not much larger) */ wrkbl = *n * 3 + (*m + *n) * ilaenv_(&c__1, "DGEBRD", " ", m, n, &c_n1, &c_n1); if (wntqn) { /* Computing MAX */ i__1 = wrkbl, i__2 = bdspac + *n * 3; maxwrk = max(i__1,i__2); minwrk = *n * 3 + max(*m,bdspac); } else if (wntqo) { /* Computing MAX */ i__1 = wrkbl, i__2 = *n * 3 + *n * ilaenv_(&c__1, "DORMBR" , "QLN", m, n, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *n * 3 + *n * ilaenv_(&c__1, "DORMBR" , "PRT", n, n, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = bdspac + *n * 3; wrkbl = max(i__1,i__2); maxwrk = wrkbl + *m * *n; /* Computing MAX */ i__1 = *m, i__2 = *n * *n + bdspac; minwrk = *n * 3 + max(i__1,i__2); } else if (wntqs) { /* Computing MAX */ i__1 = wrkbl, i__2 = *n * 3 + *n * ilaenv_(&c__1, "DORMBR" , "QLN", m, n, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *n * 3 + *n * ilaenv_(&c__1, "DORMBR" , "PRT", n, n, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = bdspac + *n * 3; maxwrk = max(i__1,i__2); minwrk = *n * 3 + max(*m,bdspac); } else if (wntqa) { /* Computing MAX */ i__1 = wrkbl, i__2 = *n * 3 + *m * ilaenv_(&c__1, "DORMBR" , "QLN", m, m, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *n * 3 + *n * ilaenv_(&c__1, "DORMBR" , "PRT", n, n, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = bdspac + *n * 3; maxwrk = max(i__1,i__2); minwrk = *n * 3 + max(*m,bdspac); } } } else if (minmn > 0) { /* Compute space needed for DBDSDC */ mnthr = (integer) (minmn * 11. / 6.); if (wntqn) { bdspac = *m * 7; } else { bdspac = *m * 3 * *m + (*m << 2); } if (*n >= mnthr) { if (wntqn) { /* Path 1t (N much larger than M, JOBZ='N') */ wrkbl = *m + *m * ilaenv_(&c__1, "DGELQF", " ", m, n, & c_n1, &c_n1); /* Computing MAX */ i__1 = wrkbl, i__2 = *m * 3 + (*m << 1) * ilaenv_(&c__1, "DGEBRD", " ", m, m, &c_n1, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = bdspac + *m; maxwrk = max(i__1,i__2); minwrk = bdspac + *m; } else if (wntqo) { /* Path 2t (N much larger than M, JOBZ='O') */ wrkbl = *m + *m * ilaenv_(&c__1, "DGELQF", " ", m, n, & c_n1, &c_n1); /* Computing MAX */ i__1 = wrkbl, i__2 = *m + *m * ilaenv_(&c__1, "DORGLQ", " ", m, n, m, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *m * 3 + (*m << 1) * ilaenv_(&c__1, "DGEBRD", " ", m, m, &c_n1, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *m * 3 + *m * ilaenv_(&c__1, "DORMBR" , "QLN", m, m, m, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *m * 3 + *m * ilaenv_(&c__1, "DORMBR" , "PRT", m, m, m, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = bdspac + *m * 3; wrkbl = max(i__1,i__2); maxwrk = wrkbl + (*m << 1) * *m; minwrk = bdspac + (*m << 1) * *m + *m * 3; } else if (wntqs) { /* Path 3t (N much larger than M, JOBZ='S') */ wrkbl = *m + *m * ilaenv_(&c__1, "DGELQF", " ", m, n, & c_n1, &c_n1); /* Computing MAX */ i__1 = wrkbl, i__2 = *m + *m * ilaenv_(&c__1, "DORGLQ", " ", m, n, m, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *m * 3 + (*m << 1) * ilaenv_(&c__1, "DGEBRD", " ", m, m, &c_n1, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *m * 3 + *m * ilaenv_(&c__1, "DORMBR" , "QLN", m, m, m, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *m * 3 + *m * ilaenv_(&c__1, "DORMBR" , "PRT", m, m, m, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = bdspac + *m * 3; wrkbl = max(i__1,i__2); maxwrk = wrkbl + *m * *m; minwrk = bdspac + *m * *m + *m * 3; } else if (wntqa) { /* Path 4t (N much larger than M, JOBZ='A') */ wrkbl = *m + *m * ilaenv_(&c__1, "DGELQF", " ", m, n, & c_n1, &c_n1); /* Computing MAX */ i__1 = wrkbl, i__2 = *m + *n * ilaenv_(&c__1, "DORGLQ", " ", n, n, m, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *m * 3 + (*m << 1) * ilaenv_(&c__1, "DGEBRD", " ", m, m, &c_n1, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *m * 3 + *m * ilaenv_(&c__1, "DORMBR" , "QLN", m, m, m, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *m * 3 + *m * ilaenv_(&c__1, "DORMBR" , "PRT", m, m, m, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = bdspac + *m * 3; wrkbl = max(i__1,i__2); maxwrk = wrkbl + *m * *m; minwrk = bdspac + *m * *m + *m * 3; } } else { /* Path 5t (N greater than M, but not much larger) */ wrkbl = *m * 3 + (*m + *n) * ilaenv_(&c__1, "DGEBRD", " ", m, n, &c_n1, &c_n1); if (wntqn) { /* Computing MAX */ i__1 = wrkbl, i__2 = bdspac + *m * 3; maxwrk = max(i__1,i__2); minwrk = *m * 3 + max(*n,bdspac); } else if (wntqo) { /* Computing MAX */ i__1 = wrkbl, i__2 = *m * 3 + *m * ilaenv_(&c__1, "DORMBR" , "QLN", m, m, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *m * 3 + *m * ilaenv_(&c__1, "DORMBR" , "PRT", m, n, m, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = bdspac + *m * 3; wrkbl = max(i__1,i__2); maxwrk = wrkbl + *m * *n; /* Computing MAX */ i__1 = *n, i__2 = *m * *m + bdspac; minwrk = *m * 3 + max(i__1,i__2); } else if (wntqs) { /* Computing MAX */ i__1 = wrkbl, i__2 = *m * 3 + *m * ilaenv_(&c__1, "DORMBR" , "QLN", m, m, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *m * 3 + *m * ilaenv_(&c__1, "DORMBR" , "PRT", m, n, m, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = bdspac + *m * 3; maxwrk = max(i__1,i__2); minwrk = *m * 3 + max(*n,bdspac); } else if (wntqa) { /* Computing MAX */ i__1 = wrkbl, i__2 = *m * 3 + *m * ilaenv_(&c__1, "DORMBR" , "QLN", m, m, n, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = *m * 3 + *m * ilaenv_(&c__1, "DORMBR" , "PRT", n, n, m, &c_n1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = bdspac + *m * 3; maxwrk = max(i__1,i__2); minwrk = *m * 3 + max(*n,bdspac); } } } maxwrk = max(maxwrk,minwrk); work[1] = (doublereal) maxwrk; if (*lwork < minwrk && ! lquery) { *info = -12; } } if (*info != 0) { i__1 = -(*info); xerbla_("DGESDD", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0) { return 0; } /* Get machine constants */ eps = dlamch_("P"); smlnum = sqrt(dlamch_("S")) / eps; bignum = 1. / smlnum; /* Scale A if max element outside range [SMLNUM,BIGNUM] */ anrm = dlange_("M", m, n, &a[a_offset], lda, dum); iscl = 0; if (anrm > 0. && anrm < smlnum) { iscl = 1; dlascl_("G", &c__0, &c__0, &anrm, &smlnum, m, n, &a[a_offset], lda, & ierr); } else if (anrm > bignum) { iscl = 1; dlascl_("G", &c__0, &c__0, &anrm, &bignum, m, n, &a[a_offset], lda, & ierr); } if (*m >= *n) { /* A has at least as many rows as columns. If A has sufficiently */ /* more rows than columns, first reduce using the QR */ /* decomposition (if sufficient workspace available) */ if (*m >= mnthr) { if (wntqn) { /* Path 1 (M much larger than N, JOBZ='N') */ /* No singular vectors to be computed */ itau = 1; nwork = itau + *n; /* Compute A=Q*R */ /* (Workspace: need 2*N, prefer N+N*NB) */ i__1 = *lwork - nwork + 1; dgeqrf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], & i__1, &ierr); /* Zero out below R */ i__1 = *n - 1; i__2 = *n - 1; dlaset_("L", &i__1, &i__2, &c_b227, &c_b227, &a[a_dim1 + 2], lda); ie = 1; itauq = ie + *n; itaup = itauq + *n; nwork = itaup + *n; /* Bidiagonalize R in A */ /* (Workspace: need 4*N, prefer 3*N+2*N*NB) */ i__1 = *lwork - nwork + 1; dgebrd_(n, n, &a[a_offset], lda, &s[1], &work[ie], &work[ itauq], &work[itaup], &work[nwork], &i__1, &ierr); nwork = ie + *n; /* Perform bidiagonal SVD, computing singular values only */ /* (Workspace: need N+BDSPAC) */ dbdsdc_("U", "N", n, &s[1], &work[ie], dum, &c__1, dum, &c__1, dum, idum, &work[nwork], &iwork[1], info); } else if (wntqo) { /* Path 2 (M much larger than N, JOBZ = 'O') */ /* N left singular vectors to be overwritten on A and */ /* N right singular vectors to be computed in VT */ ir = 1; /* WORK(IR) is LDWRKR by N */ if (*lwork >= *lda * *n + *n * *n + *n * 3 + bdspac) { ldwrkr = *lda; } else { ldwrkr = (*lwork - *n * *n - *n * 3 - bdspac) / *n; } itau = ir + ldwrkr * *n; nwork = itau + *n; /* Compute A=Q*R */ /* (Workspace: need N*N+2*N, prefer N*N+N+N*NB) */ i__1 = *lwork - nwork + 1; dgeqrf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], & i__1, &ierr); /* Copy R to WORK(IR), zeroing out below it */ dlacpy_("U", n, n, &a[a_offset], lda, &work[ir], &ldwrkr); i__1 = *n - 1; i__2 = *n - 1; dlaset_("L", &i__1, &i__2, &c_b227, &c_b227, &work[ir + 1], & ldwrkr); /* Generate Q in A */ /* (Workspace: need N*N+2*N, prefer N*N+N+N*NB) */ i__1 = *lwork - nwork + 1; dorgqr_(m, n, n, &a[a_offset], lda, &work[itau], &work[nwork], &i__1, &ierr); ie = itau; itauq = ie + *n; itaup = itauq + *n; nwork = itaup + *n; /* Bidiagonalize R in VT, copying result to WORK(IR) */ /* (Workspace: need N*N+4*N, prefer N*N+3*N+2*N*NB) */ i__1 = *lwork - nwork + 1; dgebrd_(n, n, &work[ir], &ldwrkr, &s[1], &work[ie], &work[ itauq], &work[itaup], &work[nwork], &i__1, &ierr); /* WORK(IU) is N by N */ iu = nwork; nwork = iu + *n * *n; /* Perform bidiagonal SVD, computing left singular vectors */ /* of bidiagonal matrix in WORK(IU) and computing right */ /* singular vectors of bidiagonal matrix in VT */ /* (Workspace: need N+N*N+BDSPAC) */ dbdsdc_("U", "I", n, &s[1], &work[ie], &work[iu], n, &vt[ vt_offset], ldvt, dum, idum, &work[nwork], &iwork[1], info); /* Overwrite WORK(IU) by left singular vectors of R */ /* and VT by right singular vectors of R */ /* (Workspace: need 2*N*N+3*N, prefer 2*N*N+2*N+N*NB) */ i__1 = *lwork - nwork + 1; dormbr_("Q", "L", "N", n, n, n, &work[ir], &ldwrkr, &work[ itauq], &work[iu], n, &work[nwork], &i__1, &ierr); i__1 = *lwork - nwork + 1; dormbr_("P", "R", "T", n, n, n, &work[ir], &ldwrkr, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__1, & ierr); /* Multiply Q in A by left singular vectors of R in */ /* WORK(IU), storing result in WORK(IR) and copying to A */ /* (Workspace: need 2*N*N, prefer N*N+M*N) */ i__1 = *m; i__2 = ldwrkr; for (i__ = 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { /* Computing MIN */ i__3 = *m - i__ + 1; chunk = min(i__3,ldwrkr); dgemm_("N", "N", &chunk, n, n, &c_b248, &a[i__ + a_dim1], lda, &work[iu], n, &c_b227, &work[ir], &ldwrkr); dlacpy_("F", &chunk, n, &work[ir], &ldwrkr, &a[i__ + a_dim1], lda); /* L10: */ } } else if (wntqs) { /* Path 3 (M much larger than N, JOBZ='S') */ /* N left singular vectors to be computed in U and */ /* N right singular vectors to be computed in VT */ ir = 1; /* WORK(IR) is N by N */ ldwrkr = *n; itau = ir + ldwrkr * *n; nwork = itau + *n; /* Compute A=Q*R */ /* (Workspace: need N*N+2*N, prefer N*N+N+N*NB) */ i__2 = *lwork - nwork + 1; dgeqrf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], & i__2, &ierr); /* Copy R to WORK(IR), zeroing out below it */ dlacpy_("U", n, n, &a[a_offset], lda, &work[ir], &ldwrkr); i__2 = *n - 1; i__1 = *n - 1; dlaset_("L", &i__2, &i__1, &c_b227, &c_b227, &work[ir + 1], & ldwrkr); /* Generate Q in A */ /* (Workspace: need N*N+2*N, prefer N*N+N+N*NB) */ i__2 = *lwork - nwork + 1; dorgqr_(m, n, n, &a[a_offset], lda, &work[itau], &work[nwork], &i__2, &ierr); ie = itau; itauq = ie + *n; itaup = itauq + *n; nwork = itaup + *n; /* Bidiagonalize R in WORK(IR) */ /* (Workspace: need N*N+4*N, prefer N*N+3*N+2*N*NB) */ i__2 = *lwork - nwork + 1; dgebrd_(n, n, &work[ir], &ldwrkr, &s[1], &work[ie], &work[ itauq], &work[itaup], &work[nwork], &i__2, &ierr); /* Perform bidiagonal SVD, computing left singular vectors */ /* of bidiagoal matrix in U and computing right singular */ /* vectors of bidiagonal matrix in VT */ /* (Workspace: need N+BDSPAC) */ dbdsdc_("U", "I", n, &s[1], &work[ie], &u[u_offset], ldu, &vt[ vt_offset], ldvt, dum, idum, &work[nwork], &iwork[1], info); /* Overwrite U by left singular vectors of R and VT */ /* by right singular vectors of R */ /* (Workspace: need N*N+3*N, prefer N*N+2*N+N*NB) */ i__2 = *lwork - nwork + 1; dormbr_("Q", "L", "N", n, n, n, &work[ir], &ldwrkr, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__2, &ierr); i__2 = *lwork - nwork + 1; dormbr_("P", "R", "T", n, n, n, &work[ir], &ldwrkr, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__2, & ierr); /* Multiply Q in A by left singular vectors of R in */ /* WORK(IR), storing result in U */ /* (Workspace: need N*N) */ dlacpy_("F", n, n, &u[u_offset], ldu, &work[ir], &ldwrkr); dgemm_("N", "N", m, n, n, &c_b248, &a[a_offset], lda, &work[ ir], &ldwrkr, &c_b227, &u[u_offset], ldu); } else if (wntqa) { /* Path 4 (M much larger than N, JOBZ='A') */ /* M left singular vectors to be computed in U and */ /* N right singular vectors to be computed in VT */ iu = 1; /* WORK(IU) is N by N */ ldwrku = *n; itau = iu + ldwrku * *n; nwork = itau + *n; /* Compute A=Q*R, copying result to U */ /* (Workspace: need N*N+2*N, prefer N*N+N+N*NB) */ i__2 = *lwork - nwork + 1; dgeqrf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], & i__2, &ierr); dlacpy_("L", m, n, &a[a_offset], lda, &u[u_offset], ldu); /* Generate Q in U */ /* (Workspace: need N*N+2*N, prefer N*N+N+N*NB) */ i__2 = *lwork - nwork + 1; dorgqr_(m, m, n, &u[u_offset], ldu, &work[itau], &work[nwork], &i__2, &ierr); /* Produce R in A, zeroing out other entries */ i__2 = *n - 1; i__1 = *n - 1; dlaset_("L", &i__2, &i__1, &c_b227, &c_b227, &a[a_dim1 + 2], lda); ie = itau; itauq = ie + *n; itaup = itauq + *n; nwork = itaup + *n; /* Bidiagonalize R in A */ /* (Workspace: need N*N+4*N, prefer N*N+3*N+2*N*NB) */ i__2 = *lwork - nwork + 1; dgebrd_(n, n, &a[a_offset], lda, &s[1], &work[ie], &work[ itauq], &work[itaup], &work[nwork], &i__2, &ierr); /* Perform bidiagonal SVD, computing left singular vectors */ /* of bidiagonal matrix in WORK(IU) and computing right */ /* singular vectors of bidiagonal matrix in VT */ /* (Workspace: need N+N*N+BDSPAC) */ dbdsdc_("U", "I", n, &s[1], &work[ie], &work[iu], n, &vt[ vt_offset], ldvt, dum, idum, &work[nwork], &iwork[1], info); /* Overwrite WORK(IU) by left singular vectors of R and VT */ /* by right singular vectors of R */ /* (Workspace: need N*N+3*N, prefer N*N+2*N+N*NB) */ i__2 = *lwork - nwork + 1; dormbr_("Q", "L", "N", n, n, n, &a[a_offset], lda, &work[ itauq], &work[iu], &ldwrku, &work[nwork], &i__2, & ierr); i__2 = *lwork - nwork + 1; dormbr_("P", "R", "T", n, n, n, &a[a_offset], lda, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__2, & ierr); /* Multiply Q in U by left singular vectors of R in */ /* WORK(IU), storing result in A */ /* (Workspace: need N*N) */ dgemm_("N", "N", m, n, n, &c_b248, &u[u_offset], ldu, &work[ iu], &ldwrku, &c_b227, &a[a_offset], lda); /* Copy left singular vectors of A from A to U */ dlacpy_("F", m, n, &a[a_offset], lda, &u[u_offset], ldu); } } else { /* M .LT. MNTHR */ /* Path 5 (M at least N, but not much larger) */ /* Reduce to bidiagonal form without QR decomposition */ ie = 1; itauq = ie + *n; itaup = itauq + *n; nwork = itaup + *n; /* Bidiagonalize A */ /* (Workspace: need 3*N+M, prefer 3*N+(M+N)*NB) */ i__2 = *lwork - nwork + 1; dgebrd_(m, n, &a[a_offset], lda, &s[1], &work[ie], &work[itauq], & work[itaup], &work[nwork], &i__2, &ierr); if (wntqn) { /* Perform bidiagonal SVD, only computing singular values */ /* (Workspace: need N+BDSPAC) */ dbdsdc_("U", "N", n, &s[1], &work[ie], dum, &c__1, dum, &c__1, dum, idum, &work[nwork], &iwork[1], info); } else if (wntqo) { iu = nwork; if (*lwork >= *m * *n + *n * 3 + bdspac) { /* WORK( IU ) is M by N */ ldwrku = *m; nwork = iu + ldwrku * *n; dlaset_("F", m, n, &c_b227, &c_b227, &work[iu], &ldwrku); } else { /* WORK( IU ) is N by N */ ldwrku = *n; nwork = iu + ldwrku * *n; /* WORK(IR) is LDWRKR by N */ ir = nwork; ldwrkr = (*lwork - *n * *n - *n * 3) / *n; } nwork = iu + ldwrku * *n; /* Perform bidiagonal SVD, computing left singular vectors */ /* of bidiagonal matrix in WORK(IU) and computing right */ /* singular vectors of bidiagonal matrix in VT */ /* (Workspace: need N+N*N+BDSPAC) */ dbdsdc_("U", "I", n, &s[1], &work[ie], &work[iu], &ldwrku, & vt[vt_offset], ldvt, dum, idum, &work[nwork], &iwork[ 1], info); /* Overwrite VT by right singular vectors of A */ /* (Workspace: need N*N+2*N, prefer N*N+N+N*NB) */ i__2 = *lwork - nwork + 1; dormbr_("P", "R", "T", n, n, n, &a[a_offset], lda, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__2, & ierr); if (*lwork >= *m * *n + *n * 3 + bdspac) { /* Overwrite WORK(IU) by left singular vectors of A */ /* (Workspace: need N*N+2*N, prefer N*N+N+N*NB) */ i__2 = *lwork - nwork + 1; dormbr_("Q", "L", "N", m, n, n, &a[a_offset], lda, &work[ itauq], &work[iu], &ldwrku, &work[nwork], &i__2, & ierr); /* Copy left singular vectors of A from WORK(IU) to A */ dlacpy_("F", m, n, &work[iu], &ldwrku, &a[a_offset], lda); } else { /* Generate Q in A */ /* (Workspace: need N*N+2*N, prefer N*N+N+N*NB) */ i__2 = *lwork - nwork + 1; dorgbr_("Q", m, n, n, &a[a_offset], lda, &work[itauq], & work[nwork], &i__2, &ierr); /* Multiply Q in A by left singular vectors of */ /* bidiagonal matrix in WORK(IU), storing result in */ /* WORK(IR) and copying to A */ /* (Workspace: need 2*N*N, prefer N*N+M*N) */ i__2 = *m; i__1 = ldwrkr; for (i__ = 1; i__1 < 0 ? i__ >= i__2 : i__ <= i__2; i__ += i__1) { /* Computing MIN */ i__3 = *m - i__ + 1; chunk = min(i__3,ldwrkr); dgemm_("N", "N", &chunk, n, n, &c_b248, &a[i__ + a_dim1], lda, &work[iu], &ldwrku, &c_b227, & work[ir], &ldwrkr); dlacpy_("F", &chunk, n, &work[ir], &ldwrkr, &a[i__ + a_dim1], lda); /* L20: */ } } } else if (wntqs) { /* Perform bidiagonal SVD, computing left singular vectors */ /* of bidiagonal matrix in U and computing right singular */ /* vectors of bidiagonal matrix in VT */ /* (Workspace: need N+BDSPAC) */ dlaset_("F", m, n, &c_b227, &c_b227, &u[u_offset], ldu); dbdsdc_("U", "I", n, &s[1], &work[ie], &u[u_offset], ldu, &vt[ vt_offset], ldvt, dum, idum, &work[nwork], &iwork[1], info); /* Overwrite U by left singular vectors of A and VT */ /* by right singular vectors of A */ /* (Workspace: need 3*N, prefer 2*N+N*NB) */ i__1 = *lwork - nwork + 1; dormbr_("Q", "L", "N", m, n, n, &a[a_offset], lda, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__1, &ierr); i__1 = *lwork - nwork + 1; dormbr_("P", "R", "T", n, n, n, &a[a_offset], lda, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__1, & ierr); } else if (wntqa) { /* Perform bidiagonal SVD, computing left singular vectors */ /* of bidiagonal matrix in U and computing right singular */ /* vectors of bidiagonal matrix in VT */ /* (Workspace: need N+BDSPAC) */ dlaset_("F", m, m, &c_b227, &c_b227, &u[u_offset], ldu); dbdsdc_("U", "I", n, &s[1], &work[ie], &u[u_offset], ldu, &vt[ vt_offset], ldvt, dum, idum, &work[nwork], &iwork[1], info); /* Set the right corner of U to identity matrix */ if (*m > *n) { i__1 = *m - *n; i__2 = *m - *n; dlaset_("F", &i__1, &i__2, &c_b227, &c_b248, &u[*n + 1 + ( *n + 1) * u_dim1], ldu); } /* Overwrite U by left singular vectors of A and VT */ /* by right singular vectors of A */ /* (Workspace: need N*N+2*N+M, prefer N*N+2*N+M*NB) */ i__1 = *lwork - nwork + 1; dormbr_("Q", "L", "N", m, m, n, &a[a_offset], lda, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__1, &ierr); i__1 = *lwork - nwork + 1; dormbr_("P", "R", "T", n, n, m, &a[a_offset], lda, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__1, & ierr); } } } else { /* A has more columns than rows. If A has sufficiently more */ /* columns than rows, first reduce using the LQ decomposition (if */ /* sufficient workspace available) */ if (*n >= mnthr) { if (wntqn) { /* Path 1t (N much larger than M, JOBZ='N') */ /* No singular vectors to be computed */ itau = 1; nwork = itau + *m; /* Compute A=L*Q */ /* (Workspace: need 2*M, prefer M+M*NB) */ i__1 = *lwork - nwork + 1; dgelqf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], & i__1, &ierr); /* Zero out above L */ i__1 = *m - 1; i__2 = *m - 1; dlaset_("U", &i__1, &i__2, &c_b227, &c_b227, &a[(a_dim1 << 1) + 1], lda); ie = 1; itauq = ie + *m; itaup = itauq + *m; nwork = itaup + *m; /* Bidiagonalize L in A */ /* (Workspace: need 4*M, prefer 3*M+2*M*NB) */ i__1 = *lwork - nwork + 1; dgebrd_(m, m, &a[a_offset], lda, &s[1], &work[ie], &work[ itauq], &work[itaup], &work[nwork], &i__1, &ierr); nwork = ie + *m; /* Perform bidiagonal SVD, computing singular values only */ /* (Workspace: need M+BDSPAC) */ dbdsdc_("U", "N", m, &s[1], &work[ie], dum, &c__1, dum, &c__1, dum, idum, &work[nwork], &iwork[1], info); } else if (wntqo) { /* Path 2t (N much larger than M, JOBZ='O') */ /* M right singular vectors to be overwritten on A and */ /* M left singular vectors to be computed in U */ ivt = 1; /* IVT is M by M */ il = ivt + *m * *m; if (*lwork >= *m * *n + *m * *m + *m * 3 + bdspac) { /* WORK(IL) is M by N */ ldwrkl = *m; chunk = *n; } else { ldwrkl = *m; chunk = (*lwork - *m * *m) / *m; } itau = il + ldwrkl * *m; nwork = itau + *m; /* Compute A=L*Q */ /* (Workspace: need M*M+2*M, prefer M*M+M+M*NB) */ i__1 = *lwork - nwork + 1; dgelqf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], & i__1, &ierr); /* Copy L to WORK(IL), zeroing about above it */ dlacpy_("L", m, m, &a[a_offset], lda, &work[il], &ldwrkl); i__1 = *m - 1; i__2 = *m - 1; dlaset_("U", &i__1, &i__2, &c_b227, &c_b227, &work[il + ldwrkl], &ldwrkl); /* Generate Q in A */ /* (Workspace: need M*M+2*M, prefer M*M+M+M*NB) */ i__1 = *lwork - nwork + 1; dorglq_(m, n, m, &a[a_offset], lda, &work[itau], &work[nwork], &i__1, &ierr); ie = itau; itauq = ie + *m; itaup = itauq + *m; nwork = itaup + *m; /* Bidiagonalize L in WORK(IL) */ /* (Workspace: need M*M+4*M, prefer M*M+3*M+2*M*NB) */ i__1 = *lwork - nwork + 1; dgebrd_(m, m, &work[il], &ldwrkl, &s[1], &work[ie], &work[ itauq], &work[itaup], &work[nwork], &i__1, &ierr); /* Perform bidiagonal SVD, computing left singular vectors */ /* of bidiagonal matrix in U, and computing right singular */ /* vectors of bidiagonal matrix in WORK(IVT) */ /* (Workspace: need M+M*M+BDSPAC) */ dbdsdc_("U", "I", m, &s[1], &work[ie], &u[u_offset], ldu, & work[ivt], m, dum, idum, &work[nwork], &iwork[1], info); /* Overwrite U by left singular vectors of L and WORK(IVT) */ /* by right singular vectors of L */ /* (Workspace: need 2*M*M+3*M, prefer 2*M*M+2*M+M*NB) */ i__1 = *lwork - nwork + 1; dormbr_("Q", "L", "N", m, m, m, &work[il], &ldwrkl, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__1, &ierr); i__1 = *lwork - nwork + 1; dormbr_("P", "R", "T", m, m, m, &work[il], &ldwrkl, &work[ itaup], &work[ivt], m, &work[nwork], &i__1, &ierr); /* Multiply right singular vectors of L in WORK(IVT) by Q */ /* in A, storing result in WORK(IL) and copying to A */ /* (Workspace: need 2*M*M, prefer M*M+M*N) */ i__1 = *n; i__2 = chunk; for (i__ = 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { /* Computing MIN */ i__3 = *n - i__ + 1; blk = min(i__3,chunk); dgemm_("N", "N", m, &blk, m, &c_b248, &work[ivt], m, &a[ i__ * a_dim1 + 1], lda, &c_b227, &work[il], & ldwrkl); dlacpy_("F", m, &blk, &work[il], &ldwrkl, &a[i__ * a_dim1 + 1], lda); /* L30: */ } } else if (wntqs) { /* Path 3t (N much larger than M, JOBZ='S') */ /* M right singular vectors to be computed in VT and */ /* M left singular vectors to be computed in U */ il = 1; /* WORK(IL) is M by M */ ldwrkl = *m; itau = il + ldwrkl * *m; nwork = itau + *m; /* Compute A=L*Q */ /* (Workspace: need M*M+2*M, prefer M*M+M+M*NB) */ i__2 = *lwork - nwork + 1; dgelqf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], & i__2, &ierr); /* Copy L to WORK(IL), zeroing out above it */ dlacpy_("L", m, m, &a[a_offset], lda, &work[il], &ldwrkl); i__2 = *m - 1; i__1 = *m - 1; dlaset_("U", &i__2, &i__1, &c_b227, &c_b227, &work[il + ldwrkl], &ldwrkl); /* Generate Q in A */ /* (Workspace: need M*M+2*M, prefer M*M+M+M*NB) */ i__2 = *lwork - nwork + 1; dorglq_(m, n, m, &a[a_offset], lda, &work[itau], &work[nwork], &i__2, &ierr); ie = itau; itauq = ie + *m; itaup = itauq + *m; nwork = itaup + *m; /* Bidiagonalize L in WORK(IU), copying result to U */ /* (Workspace: need M*M+4*M, prefer M*M+3*M+2*M*NB) */ i__2 = *lwork - nwork + 1; dgebrd_(m, m, &work[il], &ldwrkl, &s[1], &work[ie], &work[ itauq], &work[itaup], &work[nwork], &i__2, &ierr); /* Perform bidiagonal SVD, computing left singular vectors */ /* of bidiagonal matrix in U and computing right singular */ /* vectors of bidiagonal matrix in VT */ /* (Workspace: need M+BDSPAC) */ dbdsdc_("U", "I", m, &s[1], &work[ie], &u[u_offset], ldu, &vt[ vt_offset], ldvt, dum, idum, &work[nwork], &iwork[1], info); /* Overwrite U by left singular vectors of L and VT */ /* by right singular vectors of L */ /* (Workspace: need M*M+3*M, prefer M*M+2*M+M*NB) */ i__2 = *lwork - nwork + 1; dormbr_("Q", "L", "N", m, m, m, &work[il], &ldwrkl, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__2, &ierr); i__2 = *lwork - nwork + 1; dormbr_("P", "R", "T", m, m, m, &work[il], &ldwrkl, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__2, & ierr); /* Multiply right singular vectors of L in WORK(IL) by */ /* Q in A, storing result in VT */ /* (Workspace: need M*M) */ dlacpy_("F", m, m, &vt[vt_offset], ldvt, &work[il], &ldwrkl); dgemm_("N", "N", m, n, m, &c_b248, &work[il], &ldwrkl, &a[ a_offset], lda, &c_b227, &vt[vt_offset], ldvt); } else if (wntqa) { /* Path 4t (N much larger than M, JOBZ='A') */ /* N right singular vectors to be computed in VT and */ /* M left singular vectors to be computed in U */ ivt = 1; /* WORK(IVT) is M by M */ ldwkvt = *m; itau = ivt + ldwkvt * *m; nwork = itau + *m; /* Compute A=L*Q, copying result to VT */ /* (Workspace: need M*M+2*M, prefer M*M+M+M*NB) */ i__2 = *lwork - nwork + 1; dgelqf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], & i__2, &ierr); dlacpy_("U", m, n, &a[a_offset], lda, &vt[vt_offset], ldvt); /* Generate Q in VT */ /* (Workspace: need M*M+2*M, prefer M*M+M+M*NB) */ i__2 = *lwork - nwork + 1; dorglq_(n, n, m, &vt[vt_offset], ldvt, &work[itau], &work[ nwork], &i__2, &ierr); /* Produce L in A, zeroing out other entries */ i__2 = *m - 1; i__1 = *m - 1; dlaset_("U", &i__2, &i__1, &c_b227, &c_b227, &a[(a_dim1 << 1) + 1], lda); ie = itau; itauq = ie + *m; itaup = itauq + *m; nwork = itaup + *m; /* Bidiagonalize L in A */ /* (Workspace: need M*M+4*M, prefer M*M+3*M+2*M*NB) */ i__2 = *lwork - nwork + 1; dgebrd_(m, m, &a[a_offset], lda, &s[1], &work[ie], &work[ itauq], &work[itaup], &work[nwork], &i__2, &ierr); /* Perform bidiagonal SVD, computing left singular vectors */ /* of bidiagonal matrix in U and computing right singular */ /* vectors of bidiagonal matrix in WORK(IVT) */ /* (Workspace: need M+M*M+BDSPAC) */ dbdsdc_("U", "I", m, &s[1], &work[ie], &u[u_offset], ldu, & work[ivt], &ldwkvt, dum, idum, &work[nwork], &iwork[1] , info); /* Overwrite U by left singular vectors of L and WORK(IVT) */ /* by right singular vectors of L */ /* (Workspace: need M*M+3*M, prefer M*M+2*M+M*NB) */ i__2 = *lwork - nwork + 1; dormbr_("Q", "L", "N", m, m, m, &a[a_offset], lda, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__2, &ierr); i__2 = *lwork - nwork + 1; dormbr_("P", "R", "T", m, m, m, &a[a_offset], lda, &work[ itaup], &work[ivt], &ldwkvt, &work[nwork], &i__2, & ierr); /* Multiply right singular vectors of L in WORK(IVT) by */ /* Q in VT, storing result in A */ /* (Workspace: need M*M) */ dgemm_("N", "N", m, n, m, &c_b248, &work[ivt], &ldwkvt, &vt[ vt_offset], ldvt, &c_b227, &a[a_offset], lda); /* Copy right singular vectors of A from A to VT */ dlacpy_("F", m, n, &a[a_offset], lda, &vt[vt_offset], ldvt); } } else { /* N .LT. MNTHR */ /* Path 5t (N greater than M, but not much larger) */ /* Reduce to bidiagonal form without LQ decomposition */ ie = 1; itauq = ie + *m; itaup = itauq + *m; nwork = itaup + *m; /* Bidiagonalize A */ /* (Workspace: need 3*M+N, prefer 3*M+(M+N)*NB) */ i__2 = *lwork - nwork + 1; dgebrd_(m, n, &a[a_offset], lda, &s[1], &work[ie], &work[itauq], & work[itaup], &work[nwork], &i__2, &ierr); if (wntqn) { /* Perform bidiagonal SVD, only computing singular values */ /* (Workspace: need M+BDSPAC) */ dbdsdc_("L", "N", m, &s[1], &work[ie], dum, &c__1, dum, &c__1, dum, idum, &work[nwork], &iwork[1], info); } else if (wntqo) { ldwkvt = *m; ivt = nwork; if (*lwork >= *m * *n + *m * 3 + bdspac) { /* WORK( IVT ) is M by N */ dlaset_("F", m, n, &c_b227, &c_b227, &work[ivt], &ldwkvt); nwork = ivt + ldwkvt * *n; } else { /* WORK( IVT ) is M by M */ nwork = ivt + ldwkvt * *m; il = nwork; /* WORK(IL) is M by CHUNK */ chunk = (*lwork - *m * *m - *m * 3) / *m; } /* Perform bidiagonal SVD, computing left singular vectors */ /* of bidiagonal matrix in U and computing right singular */ /* vectors of bidiagonal matrix in WORK(IVT) */ /* (Workspace: need M*M+BDSPAC) */ dbdsdc_("L", "I", m, &s[1], &work[ie], &u[u_offset], ldu, & work[ivt], &ldwkvt, dum, idum, &work[nwork], &iwork[1] , info); /* Overwrite U by left singular vectors of A */ /* (Workspace: need M*M+2*M, prefer M*M+M+M*NB) */ i__2 = *lwork - nwork + 1; dormbr_("Q", "L", "N", m, m, n, &a[a_offset], lda, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__2, &ierr); if (*lwork >= *m * *n + *m * 3 + bdspac) { /* Overwrite WORK(IVT) by left singular vectors of A */ /* (Workspace: need M*M+2*M, prefer M*M+M+M*NB) */ i__2 = *lwork - nwork + 1; dormbr_("P", "R", "T", m, n, m, &a[a_offset], lda, &work[ itaup], &work[ivt], &ldwkvt, &work[nwork], &i__2, &ierr); /* Copy right singular vectors of A from WORK(IVT) to A */ dlacpy_("F", m, n, &work[ivt], &ldwkvt, &a[a_offset], lda); } else { /* Generate P**T in A */ /* (Workspace: need M*M+2*M, prefer M*M+M+M*NB) */ i__2 = *lwork - nwork + 1; dorgbr_("P", m, n, m, &a[a_offset], lda, &work[itaup], & work[nwork], &i__2, &ierr); /* Multiply Q in A by right singular vectors of */ /* bidiagonal matrix in WORK(IVT), storing result in */ /* WORK(IL) and copying to A */ /* (Workspace: need 2*M*M, prefer M*M+M*N) */ i__2 = *n; i__1 = chunk; for (i__ = 1; i__1 < 0 ? i__ >= i__2 : i__ <= i__2; i__ += i__1) { /* Computing MIN */ i__3 = *n - i__ + 1; blk = min(i__3,chunk); dgemm_("N", "N", m, &blk, m, &c_b248, &work[ivt], & ldwkvt, &a[i__ * a_dim1 + 1], lda, &c_b227, & work[il], m); dlacpy_("F", m, &blk, &work[il], m, &a[i__ * a_dim1 + 1], lda); /* L40: */ } } } else if (wntqs) { /* Perform bidiagonal SVD, computing left singular vectors */ /* of bidiagonal matrix in U and computing right singular */ /* vectors of bidiagonal matrix in VT */ /* (Workspace: need M+BDSPAC) */ dlaset_("F", m, n, &c_b227, &c_b227, &vt[vt_offset], ldvt); dbdsdc_("L", "I", m, &s[1], &work[ie], &u[u_offset], ldu, &vt[ vt_offset], ldvt, dum, idum, &work[nwork], &iwork[1], info); /* Overwrite U by left singular vectors of A and VT */ /* by right singular vectors of A */ /* (Workspace: need 3*M, prefer 2*M+M*NB) */ i__1 = *lwork - nwork + 1; dormbr_("Q", "L", "N", m, m, n, &a[a_offset], lda, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__1, &ierr); i__1 = *lwork - nwork + 1; dormbr_("P", "R", "T", m, n, m, &a[a_offset], lda, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__1, & ierr); } else if (wntqa) { /* Perform bidiagonal SVD, computing left singular vectors */ /* of bidiagonal matrix in U and computing right singular */ /* vectors of bidiagonal matrix in VT */ /* (Workspace: need M+BDSPAC) */ dlaset_("F", n, n, &c_b227, &c_b227, &vt[vt_offset], ldvt); dbdsdc_("L", "I", m, &s[1], &work[ie], &u[u_offset], ldu, &vt[ vt_offset], ldvt, dum, idum, &work[nwork], &iwork[1], info); /* Set the right corner of VT to identity matrix */ if (*n > *m) { i__1 = *n - *m; i__2 = *n - *m; dlaset_("F", &i__1, &i__2, &c_b227, &c_b248, &vt[*m + 1 + (*m + 1) * vt_dim1], ldvt); } /* Overwrite U by left singular vectors of A and VT */ /* by right singular vectors of A */ /* (Workspace: need 2*M+N, prefer 2*M+N*NB) */ i__1 = *lwork - nwork + 1; dormbr_("Q", "L", "N", m, m, n, &a[a_offset], lda, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__1, &ierr); i__1 = *lwork - nwork + 1; dormbr_("P", "R", "T", n, n, m, &a[a_offset], lda, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__1, & ierr); } } } /* Undo scaling if necessary */ if (iscl == 1) { if (anrm > bignum) { dlascl_("G", &c__0, &c__0, &bignum, &anrm, &minmn, &c__1, &s[1], & minmn, &ierr); } if (anrm < smlnum) { dlascl_("G", &c__0, &c__0, &smlnum, &anrm, &minmn, &c__1, &s[1], & minmn, &ierr); } } /* Return optimal workspace in WORK(1) */ work[1] = (doublereal) maxwrk; return 0; /* End of DGESDD */ } /* dgesdd_ */