/* fortran/dormtr.f -- translated by f2c (version 20200916).
   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
*/

#ifdef __cplusplus
extern "C" {
#endif
#include "lmp_f2c.h"

/* Table of constant values */

static integer c__1 = 1;
static integer c_n1 = -1;
static integer c__2 = 2;

/* > \brief \b DORMTR */

/*  =========== DOCUMENTATION =========== */

/* Online html documentation available at */
/*            http://www.netlib.org/lapack/explore-html/ */

/* > \htmlonly */
/* > Download DORMTR + dependencies */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dormtr.
f"> */
/* > [TGZ]</a> */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dormtr.
f"> */
/* > [ZIP]</a> */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dormtr.
f"> */
/* > [TXT]</a> */
/* > \endhtmlonly */

/*  Definition: */
/*  =========== */

/*       SUBROUTINE DORMTR( SIDE, UPLO, TRANS, M, N, A, LDA, TAU, C, LDC, */
/*                          WORK, LWORK, INFO ) */

/*       .. Scalar Arguments .. */
/*       CHARACTER          SIDE, TRANS, UPLO */
/*       INTEGER            INFO, LDA, LDC, LWORK, M, N */
/*       .. */
/*       .. Array Arguments .. */
/*       DOUBLE PRECISION   A( LDA, * ), C( LDC, * ), TAU( * ), WORK( * ) */
/*       .. */


/* > \par Purpose: */
/*  ============= */
/* > */
/* > \verbatim */
/* > */
/* > DORMTR overwrites the general real M-by-N matrix C with */
/* > */
/* >                 SIDE = 'L'     SIDE = 'R' */
/* > TRANS = 'N':      Q * C          C * Q */
/* > TRANS = 'T':      Q**T * C       C * Q**T */
/* > */
/* > where Q is a real orthogonal matrix of order nq, with nq = m if */
/* > SIDE = 'L' and nq = n if SIDE = 'R'. Q is defined as the product of */
/* > nq-1 elementary reflectors, as returned by DSYTRD: */
/* > */
/* > if UPLO = 'U', Q = H(nq-1) . . . H(2) H(1); */
/* > */
/* > if UPLO = 'L', Q = H(1) H(2) . . . H(nq-1). */
/* > \endverbatim */

/*  Arguments: */
/*  ========== */

/* > \param[in] SIDE */
/* > \verbatim */
/* >          SIDE is CHARACTER*1 */
/* >          = 'L': apply Q or Q**T from the Left; */
/* >          = 'R': apply Q or Q**T from the Right. */
/* > \endverbatim */
/* > */
/* > \param[in] UPLO */
/* > \verbatim */
/* >          UPLO is CHARACTER*1 */
/* >          = 'U': Upper triangle of A contains elementary reflectors */
/* >                 from DSYTRD; */
/* >          = 'L': Lower triangle of A contains elementary reflectors */
/* >                 from DSYTRD. */
/* > \endverbatim */
/* > */
/* > \param[in] TRANS */
/* > \verbatim */
/* >          TRANS is CHARACTER*1 */
/* >          = 'N':  No transpose, apply Q; */
/* >          = 'T':  Transpose, apply Q**T. */
/* > \endverbatim */
/* > */
/* > \param[in] M */
/* > \verbatim */
/* >          M is INTEGER */
/* >          The number of rows of the matrix C. M >= 0. */
/* > \endverbatim */
/* > */
/* > \param[in] N */
/* > \verbatim */
/* >          N is INTEGER */
/* >          The number of columns of the matrix C. N >= 0. */
/* > \endverbatim */
/* > */
/* > \param[in] A */
/* > \verbatim */
/* >          A is DOUBLE PRECISION array, dimension */
/* >                               (LDA,M) if SIDE = 'L' */
/* >                               (LDA,N) if SIDE = 'R' */
/* >          The vectors which define the elementary reflectors, as */
/* >          returned by DSYTRD. */
/* > \endverbatim */
/* > */
/* > \param[in] LDA */
/* > \verbatim */
/* >          LDA is INTEGER */
/* >          The leading dimension of the array A. */
/* >          LDA >= max(1,M) if SIDE = 'L'; LDA >= max(1,N) if SIDE = 'R'. */
/* > \endverbatim */
/* > */
/* > \param[in] TAU */
/* > \verbatim */
/* >          TAU is DOUBLE PRECISION array, dimension */
/* >                               (M-1) if SIDE = 'L' */
/* >                               (N-1) if SIDE = 'R' */
/* >          TAU(i) must contain the scalar factor of the elementary */
/* >          reflector H(i), as returned by DSYTRD. */
/* > \endverbatim */
/* > */
/* > \param[in,out] C */
/* > \verbatim */
/* >          C is DOUBLE PRECISION array, dimension (LDC,N) */
/* >          On entry, the M-by-N matrix C. */
/* >          On exit, C is overwritten by Q*C or Q**T*C or C*Q**T or C*Q. */
/* > \endverbatim */
/* > */
/* > \param[in] LDC */
/* > \verbatim */
/* >          LDC is INTEGER */
/* >          The leading dimension of the array C. LDC >= max(1,M). */
/* > \endverbatim */
/* > */
/* > \param[out] WORK */
/* > \verbatim */
/* >          WORK is DOUBLE PRECISION array, dimension (MAX(1,LWORK)) */
/* >          On exit, if INFO = 0, WORK(1) returns the optimal LWORK. */
/* > \endverbatim */
/* > */
/* > \param[in] LWORK */
/* > \verbatim */
/* >          LWORK is INTEGER */
/* >          The dimension of the array WORK. */
/* >          If SIDE = 'L', LWORK >= max(1,N); */
/* >          if SIDE = 'R', LWORK >= max(1,M). */
/* >          For optimum performance LWORK >= N*NB if SIDE = 'L', and */
/* >          LWORK >= M*NB if SIDE = 'R', where NB is the optimal */
/* >          blocksize. */
/* > */
/* >          If LWORK = -1, then a workspace query is assumed; the routine */
/* >          only calculates the optimal size of the WORK array, returns */
/* >          this value as the first entry of the WORK array, and no error */
/* >          message related to LWORK is issued by XERBLA. */
/* > \endverbatim */
/* > */
/* > \param[out] INFO */
/* > \verbatim */
/* >          INFO is INTEGER */
/* >          = 0:  successful exit */
/* >          < 0:  if INFO = -i, the i-th argument had an illegal value */
/* > \endverbatim */

/*  Authors: */
/*  ======== */

/* > \author Univ. of Tennessee */
/* > \author Univ. of California Berkeley */
/* > \author Univ. of Colorado Denver */
/* > \author NAG Ltd. */

/* > \ingroup doubleOTHERcomputational */

/*  ===================================================================== */
/* Subroutine */ int dormtr_(char *side, char *uplo, char *trans, integer *m,
        integer *n, doublereal *a, integer *lda, doublereal *tau, doublereal *
        c__, integer *ldc, doublereal *work, integer *lwork, integer *info,
        ftnlen side_len, ftnlen uplo_len, ftnlen trans_len)
{
    /* System generated locals */
    address a__1[2];
    integer a_dim1, a_offset, c_dim1, c_offset, i__1[2], i__2, i__3;
    char ch__1[2];

    /* Builtin functions */
    /* Subroutine */ int s_cat(char *, char **, integer *, integer *, ftnlen);

    /* Local variables */
    integer i1, i2, nb, mi, ni, nq, nw;
    logical left;
    extern logical lsame_(char *, char *, ftnlen, ftnlen);
    integer iinfo;
    logical upper;
    extern /* Subroutine */ int xerbla_(char *, integer *, ftnlen);
    extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
            integer *, integer *, ftnlen, ftnlen);
    extern /* Subroutine */ int dormql_(char *, char *, integer *, integer *,
            integer *, doublereal *, integer *, doublereal *, doublereal *,
            integer *, doublereal *, integer *, integer *, ftnlen, ftnlen),
            dormqr_(char *, char *, integer *, integer *, integer *,
            doublereal *, integer *, doublereal *, doublereal *, integer *,
            doublereal *, integer *, integer *, ftnlen, ftnlen);
    integer lwkopt;
    logical lquery;


/*  -- LAPACK computational routine -- */
/*  -- LAPACK is a software package provided by Univ. of Tennessee,    -- */
/*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  ===================================================================== */

/*     .. Local Scalars .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     Test the input arguments */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --tau;
    c_dim1 = *ldc;
    c_offset = 1 + c_dim1;
    c__ -= c_offset;
    --work;

    /* Function Body */
    *info = 0;
    left = lsame_(side, (char *)"L", (ftnlen)1, (ftnlen)1);
    upper = lsame_(uplo, (char *)"U", (ftnlen)1, (ftnlen)1);
    lquery = *lwork == -1;

/*     NQ is the order of Q and NW is the minimum dimension of WORK */

    if (left) {
        nq = *m;
        nw = max(1,*n);
    } else {
        nq = *n;
        nw = max(1,*m);
    }
    if (! left && ! lsame_(side, (char *)"R", (ftnlen)1, (ftnlen)1)) {
        *info = -1;
    } else if (! upper && ! lsame_(uplo, (char *)"L", (ftnlen)1, (ftnlen)1)) {
        *info = -2;
    } else if (! lsame_(trans, (char *)"N", (ftnlen)1, (ftnlen)1) && ! lsame_(trans,
            (char *)"T", (ftnlen)1, (ftnlen)1)) {
        *info = -3;
    } else if (*m < 0) {
        *info = -4;
    } else if (*n < 0) {
        *info = -5;
    } else if (*lda < max(1,nq)) {
        *info = -7;
    } else if (*ldc < max(1,*m)) {
        *info = -10;
    } else if (*lwork < nw && ! lquery) {
        *info = -12;
    }

    if (*info == 0) {
        if (upper) {
            if (left) {
/* Writing concatenation */
                i__1[0] = 1, a__1[0] = side;
                i__1[1] = 1, a__1[1] = trans;
                s_cat(ch__1, a__1, i__1, &c__2, (ftnlen)2);
                i__2 = *m - 1;
                i__3 = *m - 1;
                nb = ilaenv_(&c__1, (char *)"DORMQL", ch__1, &i__2, n, &i__3, &c_n1, (
                        ftnlen)6, (ftnlen)2);
            } else {
/* Writing concatenation */
                i__1[0] = 1, a__1[0] = side;
                i__1[1] = 1, a__1[1] = trans;
                s_cat(ch__1, a__1, i__1, &c__2, (ftnlen)2);
                i__2 = *n - 1;
                i__3 = *n - 1;
                nb = ilaenv_(&c__1, (char *)"DORMQL", ch__1, m, &i__2, &i__3, &c_n1, (
                        ftnlen)6, (ftnlen)2);
            }
        } else {
            if (left) {
/* Writing concatenation */
                i__1[0] = 1, a__1[0] = side;
                i__1[1] = 1, a__1[1] = trans;
                s_cat(ch__1, a__1, i__1, &c__2, (ftnlen)2);
                i__2 = *m - 1;
                i__3 = *m - 1;
                nb = ilaenv_(&c__1, (char *)"DORMQR", ch__1, &i__2, n, &i__3, &c_n1, (
                        ftnlen)6, (ftnlen)2);
            } else {
/* Writing concatenation */
                i__1[0] = 1, a__1[0] = side;
                i__1[1] = 1, a__1[1] = trans;
                s_cat(ch__1, a__1, i__1, &c__2, (ftnlen)2);
                i__2 = *n - 1;
                i__3 = *n - 1;
                nb = ilaenv_(&c__1, (char *)"DORMQR", ch__1, m, &i__2, &i__3, &c_n1, (
                        ftnlen)6, (ftnlen)2);
            }
        }
        lwkopt = nw * nb;
        work[1] = (doublereal) lwkopt;
    }

    if (*info != 0) {
        i__2 = -(*info);
        xerbla_((char *)"DORMTR", &i__2, (ftnlen)6);
        return 0;
    } else if (lquery) {
        return 0;
    }

/*     Quick return if possible */

    if (*m == 0 || *n == 0 || nq == 1) {
        work[1] = 1.;
        return 0;
    }

    if (left) {
        mi = *m - 1;
        ni = *n;
    } else {
        mi = *m;
        ni = *n - 1;
    }

    if (upper) {

/*        Q was determined by a call to DSYTRD with UPLO = 'U' */

        i__2 = nq - 1;
        dormql_(side, trans, &mi, &ni, &i__2, &a[(a_dim1 << 1) + 1], lda, &
                tau[1], &c__[c_offset], ldc, &work[1], lwork, &iinfo, (ftnlen)
                1, (ftnlen)1);
    } else {

/*        Q was determined by a call to DSYTRD with UPLO = 'L' */

        if (left) {
            i1 = 2;
            i2 = 1;
        } else {
            i1 = 1;
            i2 = 2;
        }
        i__2 = nq - 1;
        dormqr_(side, trans, &mi, &ni, &i__2, &a[a_dim1 + 2], lda, &tau[1], &
                c__[i1 + i2 * c_dim1], ldc, &work[1], lwork, &iinfo, (ftnlen)
                1, (ftnlen)1);
    }
    work[1] = (doublereal) lwkopt;
    return 0;

/*     End of DORMTR */

} /* dormtr_ */

#ifdef __cplusplus
        }
#endif