text: #include "blaswrap.h"
  #include "f2c.h"
  
  /* Subroutine */ int dlaqtr_(logical *ltran, logical *lreal, integer *n, 
  	doublereal *t, integer *ldt, doublereal *b, doublereal *w, doublereal 
  	*scale, doublereal *x, doublereal *work, integer *info)
  {
  /*  -- LAPACK auxiliary routine (version 3.1) --   
         Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..   
         November 2006   
  
  
      Purpose   
      =======   
  
      DLAQTR solves the real quasi-triangular system   
  
                   op(T)*p = scale*c,               if LREAL = .TRUE.   
  
      or the complex quasi-triangular systems   
  
                 op(T + iB)*(p+iq) = scale*(c+id),  if LREAL = .FALSE.   
  
      in real arithmetic, where T is upper quasi-triangular.   
      If LREAL = .FALSE., then the first diagonal block of T must be   
      1 by 1, B is the specially structured matrix   
  
                     B = [ b(1) b(2) ... b(n) ]   
                         [       w            ]   
                         [           w        ]   
                         [              .     ]   
                         [                 w  ]   
  
      op(A) = A or A', A' denotes the conjugate transpose of   
      matrix A.   
  
      On input, X = [ c ].  On output, X = [ p ].   
                    [ d ]                  [ q ]   
  
      This subroutine is designed for the condition number estimation   
      in routine DTRSNA.   
  
      Arguments   
      =========   
  
      LTRAN   (input) LOGICAL   
              On entry, LTRAN specifies the option of conjugate transpose:   
                 = .FALSE.,    op(T+i*B) = T+i*B,   
                 = .TRUE.,     op(T+i*B) = (T+i*B)'.   
  
      LREAL   (input) LOGICAL   
              On entry, LREAL specifies the input matrix structure:   
                 = .FALSE.,    the input is complex   
                 = .TRUE.,     the input is real   
  
      N       (input) INTEGER   
              On entry, N specifies the order of T+i*B. N >= 0.   
  
      T       (input) DOUBLE PRECISION array, dimension (LDT,N)   
              On entry, T contains a matrix in Schur canonical form.   
              If LREAL = .FALSE., then the first diagonal block of T mu   
              be 1 by 1.   
  
      LDT     (input) INTEGER   
              The leading dimension of the matrix T. LDT >= max(1,N).   
  
      B       (input) DOUBLE PRECISION array, dimension (N)   
              On entry, B contains the elements to form the matrix   
              B as described above.   
              If LREAL = .TRUE., B is not referenced.   
  
      W       (input) DOUBLE PRECISION   
              On entry, W is the diagonal element of the matrix B.   
              If LREAL = .TRUE., W is not referenced.   
  
      SCALE   (output) DOUBLE PRECISION   
              On exit, SCALE is the scale factor.   
  
      X       (input/output) DOUBLE PRECISION array, dimension (2*N)   
              On entry, X contains the right hand side of the system.   
              On exit, X is overwritten by the solution.   
  
      WORK    (workspace) DOUBLE PRECISION array, dimension (N)   
  
      INFO    (output) INTEGER   
              On exit, INFO is set to   
                 0: successful exit.   
                   1: the some diagonal 1 by 1 block has been perturbed by   
                      a small number SMIN to keep nonsingularity.   
                   2: the some diagonal 2 by 2 block has been perturbed by   
                      a small number in DLALN2 to keep nonsingularity.   
              NOTE: In the interests of speed, this routine does not   
                    check the inputs for errors.   
  
     =====================================================================   
  
  
         Do not test the input parameters for errors   
  
         Parameter adjustments */
      /* Table of constant values */
      static integer c__1 = 1;
      static logical c_false = FALSE_;
      static integer c__2 = 2;
      static doublereal c_b21 = 1.;
      static doublereal c_b25 = 0.;
      static logical c_true = TRUE_;
      
      /* System generated locals */
      integer t_dim1, t_offset, i__1, i__2;
      doublereal d__1, d__2, d__3, d__4, d__5, d__6;
      /* Local variables */
      static doublereal d__[4]	/* was [2][2] */;
      static integer i__, j, k;
      static doublereal v[4]	/* was [2][2] */, z__;
      static integer j1, j2, n1, n2;
      static doublereal si, xj, sr, rec, eps, tjj, tmp;
      extern doublereal ddot_(integer *, doublereal *, integer *, doublereal *, 
  	    integer *);
      static integer ierr;
      static doublereal smin, xmax;
      extern /* Subroutine */ int dscal_(integer *, doublereal *, doublereal *, 
  	    integer *);
      extern doublereal dasum_(integer *, doublereal *, integer *);
      extern /* Subroutine */ int daxpy_(integer *, doublereal *, doublereal *, 
  	    integer *, doublereal *, integer *);
      static integer jnext;
      static doublereal sminw, xnorm;
      extern /* Subroutine */ int dlaln2_(logical *, integer *, integer *, 
  	    doublereal *, doublereal *, doublereal *, integer *, doublereal *,
  	     doublereal *, doublereal *, integer *, doublereal *, doublereal *
  	    , doublereal *, integer *, doublereal *, doublereal *, integer *);
      extern doublereal dlamch_(char *), dlange_(char *, integer *, 
  	    integer *, doublereal *, integer *, doublereal *);
      extern integer idamax_(integer *, doublereal *, integer *);
      static doublereal scaloc;
      extern /* Subroutine */ int dladiv_(doublereal *, doublereal *, 
  	    doublereal *, doublereal *, doublereal *, doublereal *);
      static doublereal bignum;
      static logical notran;
      static doublereal smlnum;
  
  
      t_dim1 = *ldt;
      t_offset = 1 + t_dim1;
      t -= t_offset;
      --b;
      --x;
      --work;
  
      /* Function Body */
      notran = ! (*ltran);
      *info = 0;
  
  /*     Quick return if possible */
  
      if (*n == 0) {
  	return 0;
      }
  
  /*     Set constants to control overflow */
  
      eps = dlamch_("P");
      smlnum = dlamch_("S") / eps;
      bignum = 1. / smlnum;
  
      xnorm = dlange_("M", n, n, &t[t_offset], ldt, d__);
      if (! (*lreal)) {
  /* Computing MAX */
  	d__1 = xnorm, d__2 = abs(*w), d__1 = max(d__1,d__2), d__2 = dlange_(
  		"M", n, &c__1, &b[1], n, d__);
  	xnorm = max(d__1,d__2);
      }
  /* Computing MAX */
      d__1 = smlnum, d__2 = eps * xnorm;
      smin = max(d__1,d__2);
  
  /*     Compute 1-norm of each column of strictly upper triangular   
         part of T to control overflow in triangular solver. */
  
      work[1] = 0.;
      i__1 = *n;
      for (j = 2; j <= i__1; ++j) {
  	i__2 = j - 1;
  	work[j] = dasum_(&i__2, &t[j * t_dim1 + 1], &c__1);
  /* L10: */
      }
  
      if (! (*lreal)) {
  	i__1 = *n;
  	for (i__ = 2; i__ <= i__1; ++i__) {
  	    work[i__] += (d__1 = b[i__], abs(d__1));
  /* L20: */
  	}
      }
  
      n2 = *n << 1;
      n1 = *n;
      if (! (*lreal)) {
  	n1 = n2;
      }
      k = idamax_(&n1, &x[1], &c__1);
      xmax = (d__1 = x[k], abs(d__1));
      *scale = 1.;
  
      if (xmax > bignum) {
  	*scale = bignum / xmax;
  	dscal_(&n1, scale, &x[1], &c__1);
  	xmax = bignum;
      }
  
      if (*lreal) {
  
  	if (notran) {
  
  /*           Solve T*p = scale*c */
  
  	    jnext = *n;
  	    for (j = *n; j >= 1; --j) {
  		if (j > jnext) {
  		    goto L30;
  		}
  		j1 = j;
  		j2 = j;
  		jnext = j - 1;
  		if (j > 1) {
  		    if (t[j + (j - 1) * t_dim1] != 0.) {
  			j1 = j - 1;
  			jnext = j - 2;
  		    }
  		}
  
  		if (j1 == j2) {
  
  /*                 Meet 1 by 1 diagonal block   
  
                     Scale to avoid overflow when computing   
                         x(j) = b(j)/T(j,j) */
  
  		    xj = (d__1 = x[j1], abs(d__1));
  		    tjj = (d__1 = t[j1 + j1 * t_dim1], abs(d__1));
  		    tmp = t[j1 + j1 * t_dim1];
  		    if (tjj < smin) {
  			tmp = smin;
  			tjj = smin;
  			*info = 1;
  		    }
  
  		    if (xj == 0.) {
  			goto L30;
  		    }
  
  		    if (tjj < 1.) {
  			if (xj > bignum * tjj) {
  			    rec = 1. / xj;
  			    dscal_(n, &rec, &x[1], &c__1);
  			    *scale *= rec;
  			    xmax *= rec;
  			}
  		    }
  		    x[j1] /= tmp;
  		    xj = (d__1 = x[j1], abs(d__1));
  
  /*                 Scale x if necessary to avoid overflow when adding a   
                     multiple of column j1 of T. */
  
  		    if (xj > 1.) {
  			rec = 1. / xj;
  			if (work[j1] > (bignum - xmax) * rec) {
  			    dscal_(n, &rec, &x[1], &c__1);
  			    *scale *= rec;
  			}
  		    }
  		    if (j1 > 1) {
  			i__1 = j1 - 1;
  			d__1 = -x[j1];
  			daxpy_(&i__1, &d__1, &t[j1 * t_dim1 + 1], &c__1, &x[1]
  , &c__1);
  			i__1 = j1 - 1;
  			k = idamax_(&i__1, &x[1], &c__1);
  			xmax = (d__1 = x[k], abs(d__1));
  		    }
  
  		} else {
  
  /*                 Meet 2 by 2 diagonal block   
  
                     Call 2 by 2 linear system solve, to take   
                     care of possible overflow by scaling factor. */
  
  		    d__[0] = x[j1];
  		    d__[1] = x[j2];
  		    dlaln2_(&c_false, &c__2, &c__1, &smin, &c_b21, &t[j1 + j1 
  			    * t_dim1], ldt, &c_b21, &c_b21, d__, &c__2, &
  			    c_b25, &c_b25, v, &c__2, &scaloc, &xnorm, &ierr);
  		    if (ierr != 0) {
  			*info = 2;
  		    }
  
  		    if (scaloc != 1.) {
  			dscal_(n, &scaloc, &x[1], &c__1);
  			*scale *= scaloc;
  		    }
  		    x[j1] = v[0];
  		    x[j2] = v[1];
  
  /*                 Scale V(1,1) (= X(J1)) and/or V(2,1) (=X(J2))   
                     to avoid overflow in updating right-hand side.   
  
     Computing MAX */
  		    d__1 = abs(v[0]), d__2 = abs(v[1]);
  		    xj = max(d__1,d__2);
  		    if (xj > 1.) {
  			rec = 1. / xj;
  /* Computing MAX */
  			d__1 = work[j1], d__2 = work[j2];
  			if (max(d__1,d__2) > (bignum - xmax) * rec) {
  			    dscal_(n, &rec, &x[1], &c__1);
  			    *scale *= rec;
  			}
  		    }
  
  /*                 Update right-hand side */
  
  		    if (j1 > 1) {
  			i__1 = j1 - 1;
  			d__1 = -x[j1];
  			daxpy_(&i__1, &d__1, &t[j1 * t_dim1 + 1], &c__1, &x[1]
  , &c__1);
  			i__1 = j1 - 1;
  			d__1 = -x[j2];
  			daxpy_(&i__1, &d__1, &t[j2 * t_dim1 + 1], &c__1, &x[1]
  , &c__1);
  			i__1 = j1 - 1;
  			k = idamax_(&i__1, &x[1], &c__1);
  			xmax = (d__1 = x[k], abs(d__1));
  		    }
  
  		}
  
  L30:
  		;
  	    }
  
  	} else {
  
  /*           Solve T'*p = scale*c */
  
  	    jnext = 1;
  	    i__1 = *n;
  	    for (j = 1; j <= i__1; ++j) {
  		if (j < jnext) {
  		    goto L40;
  		}
  		j1 = j;
  		j2 = j;
  		jnext = j + 1;
  		if (j < *n) {
  		    if (t[j + 1 + j * t_dim1] != 0.) {
  			j2 = j + 1;
  			jnext = j + 2;
  		    }
  		}
  
  		if (j1 == j2) {
  
  /*                 1 by 1 diagonal block   
  
                     Scale if necessary to avoid overflow in forming the   
                     right-hand side element by inner product. */
  
  		    xj = (d__1 = x[j1], abs(d__1));
  		    if (xmax > 1.) {
  			rec = 1. / xmax;
  			if (work[j1] > (bignum - xj) * rec) {
  			    dscal_(n, &rec, &x[1], &c__1);
  			    *scale *= rec;
  			    xmax *= rec;
  			}
  		    }
  
  		    i__2 = j1 - 1;
  		    x[j1] -= ddot_(&i__2, &t[j1 * t_dim1 + 1], &c__1, &x[1], &
  			    c__1);
  
  		    xj = (d__1 = x[j1], abs(d__1));
  		    tjj = (d__1 = t[j1 + j1 * t_dim1], abs(d__1));
  		    tmp = t[j1 + j1 * t_dim1];
  		    if (tjj < smin) {
  			tmp = smin;
  			tjj = smin;
  			*info = 1;
  		    }
  
  		    if (tjj < 1.) {
  			if (xj > bignum * tjj) {
  			    rec = 1. / xj;
  			    dscal_(n, &rec, &x[1], &c__1);
  			    *scale *= rec;
  			    xmax *= rec;
  			}
  		    }
  		    x[j1] /= tmp;
  /* Computing MAX */
  		    d__2 = xmax, d__3 = (d__1 = x[j1], abs(d__1));
  		    xmax = max(d__2,d__3);
  
  		} else {
  
  /*                 2 by 2 diagonal block   
  
                     Scale if necessary to avoid overflow in forming the   
                     right-hand side elements by inner product.   
  
     Computing MAX */
  		    d__3 = (d__1 = x[j1], abs(d__1)), d__4 = (d__2 = x[j2], 
  			    abs(d__2));
  		    xj = max(d__3,d__4);
  		    if (xmax > 1.) {
  			rec = 1. / xmax;
  /* Computing MAX */
  			d__1 = work[j2], d__2 = work[j1];
  			if (max(d__1,d__2) > (bignum - xj) * rec) {
  			    dscal_(n, &rec, &x[1], &c__1);
  			    *scale *= rec;
  			    xmax *= rec;
  			}
  		    }
  
  		    i__2 = j1 - 1;
  		    d__[0] = x[j1] - ddot_(&i__2, &t[j1 * t_dim1 + 1], &c__1, 
  			    &x[1], &c__1);
  		    i__2 = j1 - 1;
  		    d__[1] = x[j2] - ddot_(&i__2, &t[j2 * t_dim1 + 1], &c__1, 
  			    &x[1], &c__1);
  
  		    dlaln2_(&c_true, &c__2, &c__1, &smin, &c_b21, &t[j1 + j1 *
  			     t_dim1], ldt, &c_b21, &c_b21, d__, &c__2, &c_b25,
  			     &c_b25, v, &c__2, &scaloc, &xnorm, &ierr);
  		    if (ierr != 0) {
  			*info = 2;
  		    }
  
  		    if (scaloc != 1.) {
  			dscal_(n, &scaloc, &x[1], &c__1);
  			*scale *= scaloc;
  		    }
  		    x[j1] = v[0];
  		    x[j2] = v[1];
  /* Computing MAX */
  		    d__3 = (d__1 = x[j1], abs(d__1)), d__4 = (d__2 = x[j2], 
  			    abs(d__2)), d__3 = max(d__3,d__4);
  		    xmax = max(d__3,xmax);
  
  		}
  L40:
  		;
  	    }
  	}
  
      } else {
  
  /* Computing MAX */
  	d__1 = eps * abs(*w);
  	sminw = max(d__1,smin);
  	if (notran) {
  
  /*           Solve (T + iB)*(p+iq) = c+id */
  
  	    jnext = *n;
  	    for (j = *n; j >= 1; --j) {
  		if (j > jnext) {
  		    goto L70;
  		}
  		j1 = j;
  		j2 = j;
  		jnext = j - 1;
  		if (j > 1) {
  		    if (t[j + (j - 1) * t_dim1] != 0.) {
  			j1 = j - 1;
  			jnext = j - 2;
  		    }
  		}
  
  		if (j1 == j2) {
  
  /*                 1 by 1 diagonal block   
  
                     Scale if necessary to avoid overflow in division */
  
  		    z__ = *w;
  		    if (j1 == 1) {
  			z__ = b[1];
  		    }
  		    xj = (d__1 = x[j1], abs(d__1)) + (d__2 = x[*n + j1], abs(
  			    d__2));
  		    tjj = (d__1 = t[j1 + j1 * t_dim1], abs(d__1)) + abs(z__);
  		    tmp = t[j1 + j1 * t_dim1];
  		    if (tjj < sminw) {
  			tmp = sminw;
  			tjj = sminw;
  			*info = 1;
  		    }
  
  		    if (xj == 0.) {
  			goto L70;
  		    }
  
  		    if (tjj < 1.) {
  			if (xj > bignum * tjj) {
  			    rec = 1. / xj;
  			    dscal_(&n2, &rec, &x[1], &c__1);
  			    *scale *= rec;
  			    xmax *= rec;
  			}
  		    }
  		    dladiv_(&x[j1], &x[*n + j1], &tmp, &z__, &sr, &si);
  		    x[j1] = sr;
  		    x[*n + j1] = si;
  		    xj = (d__1 = x[j1], abs(d__1)) + (d__2 = x[*n + j1], abs(
  			    d__2));
  
  /*                 Scale x if necessary to avoid overflow when adding a   
                     multiple of column j1 of T. */
  
  		    if (xj > 1.) {
  			rec = 1. / xj;
  			if (work[j1] > (bignum - xmax) * rec) {
  			    dscal_(&n2, &rec, &x[1], &c__1);
  			    *scale *= rec;
  			}
  		    }
  
  		    if (j1 > 1) {
  			i__1 = j1 - 1;
  			d__1 = -x[j1];
  			daxpy_(&i__1, &d__1, &t[j1 * t_dim1 + 1], &c__1, &x[1]
  , &c__1);
  			i__1 = j1 - 1;
  			d__1 = -x[*n + j1];
  			daxpy_(&i__1, &d__1, &t[j1 * t_dim1 + 1], &c__1, &x[*
  				n + 1], &c__1);
  
  			x[1] += b[j1] * x[*n + j1];
  			x[*n + 1] -= b[j1] * x[j1];
  
  			xmax = 0.;
  			i__1 = j1 - 1;
  			for (k = 1; k <= i__1; ++k) {
  /* Computing MAX */
  			    d__3 = xmax, d__4 = (d__1 = x[k], abs(d__1)) + (
  				    d__2 = x[k + *n], abs(d__2));
  			    xmax = max(d__3,d__4);
  /* L50: */
  			}
  		    }
  
  		} else {
  
  /*                 Meet 2 by 2 diagonal block */
  
  		    d__[0] = x[j1];
  		    d__[1] = x[j2];
  		    d__[2] = x[*n + j1];
  		    d__[3] = x[*n + j2];
  		    d__1 = -(*w);
  		    dlaln2_(&c_false, &c__2, &c__2, &sminw, &c_b21, &t[j1 + 
  			    j1 * t_dim1], ldt, &c_b21, &c_b21, d__, &c__2, &
  			    c_b25, &d__1, v, &c__2, &scaloc, &xnorm, &ierr);
  		    if (ierr != 0) {
  			*info = 2;
  		    }
  
  		    if (scaloc != 1.) {
  			i__1 = *n << 1;
  			dscal_(&i__1, &scaloc, &x[1], &c__1);
  			*scale = scaloc * *scale;
  		    }
  		    x[j1] = v[0];
  		    x[j2] = v[1];
  		    x[*n + j1] = v[2];
  		    x[*n + j2] = v[3];
  
  /*                 Scale X(J1), .... to avoid overflow in   
                     updating right hand side.   
  
     Computing MAX */
  		    d__1 = abs(v[0]) + abs(v[2]), d__2 = abs(v[1]) + abs(v[3])
  			    ;
  		    xj = max(d__1,d__2);
  		    if (xj > 1.) {
  			rec = 1. / xj;
  /* Computing MAX */
  			d__1 = work[j1], d__2 = work[j2];
  			if (max(d__1,d__2) > (bignum - xmax) * rec) {
  			    dscal_(&n2, &rec, &x[1], &c__1);
  			    *scale *= rec;
  			}
  		    }
  
  /*                 Update the right-hand side. */
  
  		    if (j1 > 1) {
  			i__1 = j1 - 1;
  			d__1 = -x[j1];
  			daxpy_(&i__1, &d__1, &t[j1 * t_dim1 + 1], &c__1, &x[1]
  , &c__1);
  			i__1 = j1 - 1;
  			d__1 = -x[j2];
  			daxpy_(&i__1, &d__1, &t[j2 * t_dim1 + 1], &c__1, &x[1]
  , &c__1);
  
  			i__1 = j1 - 1;
  			d__1 = -x[*n + j1];
  			daxpy_(&i__1, &d__1, &t[j1 * t_dim1 + 1], &c__1, &x[*
  				n + 1], &c__1);
  			i__1 = j1 - 1;
  			d__1 = -x[*n + j2];
  			daxpy_(&i__1, &d__1, &t[j2 * t_dim1 + 1], &c__1, &x[*
  				n + 1], &c__1);
  
  			x[1] = x[1] + b[j1] * x[*n + j1] + b[j2] * x[*n + j2];
  			x[*n + 1] = x[*n + 1] - b[j1] * x[j1] - b[j2] * x[j2];
  
  			xmax = 0.;
  			i__1 = j1 - 1;
  			for (k = 1; k <= i__1; ++k) {
  /* Computing MAX */
  			    d__3 = (d__1 = x[k], abs(d__1)) + (d__2 = x[k + *
  				    n], abs(d__2));
  			    xmax = max(d__3,xmax);
  /* L60: */
  			}
  		    }
  
  		}
  L70:
  		;
  	    }
  
  	} else {
  
  /*           Solve (T + iB)'*(p+iq) = c+id */
  
  	    jnext = 1;
  	    i__1 = *n;
  	    for (j = 1; j <= i__1; ++j) {
  		if (j < jnext) {
  		    goto L80;
  		}
  		j1 = j;
  		j2 = j;
  		jnext = j + 1;
  		if (j < *n) {
  		    if (t[j + 1 + j * t_dim1] != 0.) {
  			j2 = j + 1;
  			jnext = j + 2;
  		    }
  		}
  
  		if (j1 == j2) {
  
  /*                 1 by 1 diagonal block   
  
                     Scale if necessary to avoid overflow in forming the   
                     right-hand side element by inner product. */
  
  		    xj = (d__1 = x[j1], abs(d__1)) + (d__2 = x[j1 + *n], abs(
  			    d__2));
  		    if (xmax > 1.) {
  			rec = 1. / xmax;
  			if (work[j1] > (bignum - xj) * rec) {
  			    dscal_(&n2, &rec, &x[1], &c__1);
  			    *scale *= rec;
  			    xmax *= rec;
  			}
  		    }
  
  		    i__2 = j1 - 1;
  		    x[j1] -= ddot_(&i__2, &t[j1 * t_dim1 + 1], &c__1, &x[1], &
  			    c__1);
  		    i__2 = j1 - 1;
  		    x[*n + j1] -= ddot_(&i__2, &t[j1 * t_dim1 + 1], &c__1, &x[
  			    *n + 1], &c__1);
  		    if (j1 > 1) {
  			x[j1] -= b[j1] * x[*n + 1];
  			x[*n + j1] += b[j1] * x[1];
  		    }
  		    xj = (d__1 = x[j1], abs(d__1)) + (d__2 = x[j1 + *n], abs(
  			    d__2));
  
  		    z__ = *w;
  		    if (j1 == 1) {
  			z__ = b[1];
  		    }
  
  /*                 Scale if necessary to avoid overflow in   
                     complex division */
  
  		    tjj = (d__1 = t[j1 + j1 * t_dim1], abs(d__1)) + abs(z__);
  		    tmp = t[j1 + j1 * t_dim1];
  		    if (tjj < sminw) {
  			tmp = sminw;
  			tjj = sminw;
  			*info = 1;
  		    }
  
  		    if (tjj < 1.) {
  			if (xj > bignum * tjj) {
  			    rec = 1. / xj;
  			    dscal_(&n2, &rec, &x[1], &c__1);
  			    *scale *= rec;
  			    xmax *= rec;
  			}
  		    }
  		    d__1 = -z__;
  		    dladiv_(&x[j1], &x[*n + j1], &tmp, &d__1, &sr, &si);
  		    x[j1] = sr;
  		    x[j1 + *n] = si;
  /* Computing MAX */
  		    d__3 = (d__1 = x[j1], abs(d__1)) + (d__2 = x[j1 + *n], 
  			    abs(d__2));
  		    xmax = max(d__3,xmax);
  
  		} else {
  
  /*                 2 by 2 diagonal block   
  
                     Scale if necessary to avoid overflow in forming the   
                     right-hand side element by inner product.   
  
     Computing MAX */
  		    d__5 = (d__1 = x[j1], abs(d__1)) + (d__2 = x[*n + j1], 
  			    abs(d__2)), d__6 = (d__3 = x[j2], abs(d__3)) + (
  			    d__4 = x[*n + j2], abs(d__4));
  		    xj = max(d__5,d__6);
  		    if (xmax > 1.) {
  			rec = 1. / xmax;
  /* Computing MAX */
  			d__1 = work[j1], d__2 = work[j2];
  			if (max(d__1,d__2) > (bignum - xj) / xmax) {
  			    dscal_(&n2, &rec, &x[1], &c__1);
  			    *scale *= rec;
  			    xmax *= rec;
  			}
  		    }
  
  		    i__2 = j1 - 1;
  		    d__[0] = x[j1] - ddot_(&i__2, &t[j1 * t_dim1 + 1], &c__1, 
  			    &x[1], &c__1);
  		    i__2 = j1 - 1;
  		    d__[1] = x[j2] - ddot_(&i__2, &t[j2 * t_dim1 + 1], &c__1, 
  			    &x[1], &c__1);
  		    i__2 = j1 - 1;
  		    d__[2] = x[*n + j1] - ddot_(&i__2, &t[j1 * t_dim1 + 1], &
  			    c__1, &x[*n + 1], &c__1);
  		    i__2 = j1 - 1;
  		    d__[3] = x[*n + j2] - ddot_(&i__2, &t[j2 * t_dim1 + 1], &
  			    c__1, &x[*n + 1], &c__1);
  		    d__[0] -= b[j1] * x[*n + 1];
  		    d__[1] -= b[j2] * x[*n + 1];
  		    d__[2] += b[j1] * x[1];
  		    d__[3] += b[j2] * x[1];
  
  		    dlaln2_(&c_true, &c__2, &c__2, &sminw, &c_b21, &t[j1 + j1 
  			    * t_dim1], ldt, &c_b21, &c_b21, d__, &c__2, &
  			    c_b25, w, v, &c__2, &scaloc, &xnorm, &ierr);
  		    if (ierr != 0) {
  			*info = 2;
  		    }
  
  		    if (scaloc != 1.) {
  			dscal_(&n2, &scaloc, &x[1], &c__1);
  			*scale = scaloc * *scale;
  		    }
  		    x[j1] = v[0];
  		    x[j2] = v[1];
  		    x[*n + j1] = v[2];
  		    x[*n + j2] = v[3];
  /* Computing MAX */
  		    d__5 = (d__1 = x[j1], abs(d__1)) + (d__2 = x[*n + j1], 
  			    abs(d__2)), d__6 = (d__3 = x[j2], abs(d__3)) + (
  			    d__4 = x[*n + j2], abs(d__4)), d__5 = max(d__5,
  			    d__6);
  		    xmax = max(d__5,xmax);
  
  		}
  
  L80:
  		;
  	    }
  
  	}
  
      }
  
      return 0;
  
  /*     End of DLAQTR */
  
  } /* dlaqtr_ */
  