text: /* ../netlib/zsytf2.f -- translated by f2c (version 20100827). 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 "FLA_f2c.h" /* Table of constant values */
  static doublecomplex c_b1 =
  {
      1.,0.
  }
  ;
  static integer c__1 = 1;
  /* > \brief \b ZSYTF2 computes the factorization of a real symmetric indefinite matrix, using the diagonal piv oting method (unblocked algorithm). */
  /* =========== DOCUMENTATION =========== */
  /* Online html documentation available at */
  /* http://www.netlib.org/lapack/explore-html/ */
  /* > \htmlonly */
  /* > Download ZSYTF2 + dependencies */
  /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/zsytf2. f"> */
  /* > [TGZ]</a> */
  /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/zsytf2. f"> */
  /* > [ZIP]</a> */
  /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/zsytf2. f"> */
  /* > [TXT]</a> */
  /* > \endhtmlonly */
  /* Definition: */
  /* =========== */
  /* SUBROUTINE ZSYTF2( UPLO, N, A, LDA, IPIV, INFO ) */
  /* .. Scalar Arguments .. */
  /* CHARACTER UPLO */
  /* INTEGER INFO, LDA, N */
  /* .. */
  /* .. Array Arguments .. */
  /* INTEGER IPIV( * ) */
  /* COMPLEX*16 A( LDA, * ) */
  /* .. */
  /* > \par Purpose: */
  /* ============= */
  /* > */
  /* > \verbatim */
  /* > */
  /* > ZSYTF2 computes the factorization of a complex symmetric matrix A */
  /* > using the Bunch-Kaufman diagonal pivoting method: */
  /* > */
  /* > A = U*D*U**T or A = L*D*L**T */
  /* > */
  /* > where U (or L) is a product of permutation and unit upper (lower) */
  /* > triangular matrices, U**T is the transpose of U, and D is symmetric and */
  /* > block diagonal with 1-by-1 and 2-by-2 diagonal blocks. */
  /* > */
  /* > This is the unblocked version of the algorithm, calling Level 2 BLAS. */
  /* > \endverbatim */
  /* Arguments: */
  /* ========== */
  /* > \param[in] UPLO */
  /* > \verbatim */
  /* > UPLO is CHARACTER*1 */
  /* > Specifies whether the upper or lower triangular part of the */
  /* > symmetric matrix A is stored: */
  /* > = 'U': Upper triangular */
  /* > = 'L': Lower triangular */
  /* > \endverbatim */
  /* > */
  /* > \param[in] N */
  /* > \verbatim */
  /* > N is INTEGER */
  /* > The order of the matrix A. N >= 0. */
  /* > \endverbatim */
  /* > */
  /* > \param[in,out] A */
  /* > \verbatim */
  /* > A is COMPLEX*16 array, dimension (LDA,N) */
  /* > On entry, the symmetric matrix A. If UPLO = 'U', the leading */
  /* > n-by-n upper triangular part of A contains the upper */
  /* > triangular part of the matrix A, and the strictly lower */
  /* > triangular part of A is not referenced. If UPLO = 'L', the */
  /* > leading n-by-n lower triangular part of A contains the lower */
  /* > triangular part of the matrix A, and the strictly upper */
  /* > triangular part of A is not referenced. */
  /* > */
  /* > On exit, the block diagonal matrix D and the multipliers used */
  /* > to obtain the factor U or L (see below for further details). */
  /* > \endverbatim */
  /* > */
  /* > \param[in] LDA */
  /* > \verbatim */
  /* > LDA is INTEGER */
  /* > The leading dimension of the array A. LDA >= max(1,N). */
  /* > \endverbatim */
  /* > */
  /* > \param[out] IPIV */
  /* > \verbatim */
  /* > IPIV is INTEGER array, dimension (N) */
  /* > Details of the interchanges and the block structure of D. */
  /* > */
  /* > If UPLO = 'U': */
  /* > If IPIV(k) > 0, then rows and columns k and IPIV(k) were */
  /* > interchanged and D(k,k) is a 1-by-1 diagonal block. */
  /* > */
  /* > If IPIV(k) = IPIV(k-1) < 0, then rows and columns */
  /* > k-1 and -IPIV(k) were interchanged and D(k-1:k,k-1:k) */
  /* > is a 2-by-2 diagonal block. */
  /* > */
  /* > If UPLO = 'L': */
  /* > If IPIV(k) > 0, then rows and columns k and IPIV(k) were */
  /* > interchanged and D(k,k) is a 1-by-1 diagonal block. */
  /* > */
  /* > If IPIV(k) = IPIV(k+1) < 0, then rows and columns */
  /* > k+1 and -IPIV(k) were interchanged and D(k:k+1,k:k+1) */
  /* > is a 2-by-2 diagonal block. */
  /* > \endverbatim */
  /* > */
  /* > \param[out] INFO */
  /* > \verbatim */
  /* > INFO is INTEGER */
  /* > = 0: successful exit */
  /* > < 0: if INFO = -k, the k-th argument had an illegal value */
  /* > > 0: if INFO = k, D(k,k) is exactly zero. The factorization */
  /* > has been completed, but the block diagonal matrix D is */
  /* > exactly singular, and division by zero will occur if it */
  /* > is used to solve a system of equations. */
  /* > \endverbatim */
  /* Authors: */
  /* ======== */
  /* > \author Univ. of Tennessee */
  /* > \author Univ. of California Berkeley */
  /* > \author Univ. of Colorado Denver */
  /* > \author NAG Ltd. */
  /* > \date November 2013 */
  /* > \ingroup complex16SYcomputational */
  /* > \par Further Details: */
  /* ===================== */
  /* > */
  /* > \verbatim */
  /* > */
  /* > If UPLO = 'U', then A = U*D*U**T, where */
  /* > U = P(n)*U(n)* ... *P(k)U(k)* ..., */
  /* > i.e., U is a product of terms P(k)*U(k), where k decreases from n to */
  /* > 1 in steps of 1 or 2, and D is a block diagonal matrix with 1-by-1 */
  /* > and 2-by-2 diagonal blocks D(k). P(k) is a permutation matrix as */
  /* > defined by IPIV(k), and U(k) is a unit upper triangular matrix, such */
  /* > that if the diagonal block D(k) is of order s (s = 1 or 2), then */
  /* > */
  /* > ( I v 0 ) k-s */
  /* > U(k) = ( 0 I 0 ) s */
  /* > ( 0 0 I ) n-k */
  /* > k-s s n-k */
  /* > */
  /* > If s = 1, D(k) overwrites A(k,k), and v overwrites A(1:k-1,k). */
  /* > If s = 2, the upper triangle of D(k) overwrites A(k-1,k-1), A(k-1,k), */
  /* > and A(k,k), and v overwrites A(1:k-2,k-1:k). */
  /* > */
  /* > If UPLO = 'L', then A = L*D*L**T, where */
  /* > L = P(1)*L(1)* ... *P(k)*L(k)* ..., */
  /* > i.e., L is a product of terms P(k)*L(k), where k increases from 1 to */
  /* > n in steps of 1 or 2, and D is a block diagonal matrix with 1-by-1 */
  /* > and 2-by-2 diagonal blocks D(k). P(k) is a permutation matrix as */
  /* > defined by IPIV(k), and L(k) is a unit lower triangular matrix, such */
  /* > that if the diagonal block D(k) is of order s (s = 1 or 2), then */
  /* > */
  /* > ( I 0 0 ) k-1 */
  /* > L(k) = ( 0 I 0 ) s */
  /* > ( 0 v I ) n-k-s+1 */
  /* > k-1 s n-k-s+1 */
  /* > */
  /* > If s = 1, D(k) overwrites A(k,k), and v overwrites A(k+1:n,k). */
  /* > If s = 2, the lower triangle of D(k) overwrites A(k,k), A(k+1,k), */
  /* > and A(k+1,k+1), and v overwrites A(k+2:n,k:k+1). */
  /* > \endverbatim */
  /* > \par Contributors: */
  /* ================== */
  /* > */
  /* > \verbatim */
  /* > */
  /* > 09-29-06 - patch from */
  /* > Bobby Cheng, MathWorks */
  /* > */
  /* > Replace l.209 and l.377 */
  /* > IF( MAX( ABSAKK, COLMAX ).EQ.ZERO ) THEN */
  /* > by */
  /* > IF( (MAX( ABSAKK, COLMAX ).EQ.ZERO) .OR. DISNAN(ABSAKK) ) THEN */
  /* > */
  /* > 1-96 - Based on modifications by J. Lewis, Boeing Computer Services */
  /* > Company */
  /* > \endverbatim */
  /* ===================================================================== */
  /* Subroutine */
  int zsytf2_(char *uplo, integer *n, doublecomplex *a, integer *lda, integer *ipiv, integer *info)
  {
      /* System generated locals */
      integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5, i__6;
      doublereal d__1, d__2, d__3, d__4;
      doublecomplex z__1, z__2, z__3, z__4;
      /* Builtin functions */
      double sqrt(doublereal), d_imag(doublecomplex *);
      void z_div(doublecomplex *, doublecomplex *, doublecomplex *);
      /* Local variables */
      integer i__, j, k;
      doublecomplex t, r1, d11, d12, d21, d22;
      integer kk, kp;
      doublecomplex wk, wkm1, wkp1;
      integer imax, jmax;
      extern /* Subroutine */
      int zsyr_(char *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *);
      doublereal alpha;
      extern logical lsame_(char *, char *);
      extern /* Subroutine */
      int zscal_(integer *, doublecomplex *, doublecomplex *, integer *);
      integer kstep;
      logical upper;
      extern /* Subroutine */
      int zswap_(integer *, doublecomplex *, integer *, doublecomplex *, integer *);
      doublereal absakk;
      extern logical disnan_(doublereal *);
      extern /* Subroutine */
      int xerbla_(char *, integer *);
      doublereal colmax;
      extern integer izamax_(integer *, doublecomplex *, integer *);
      doublereal rowmax;
      /* -- LAPACK computational routine (version 3.5.0) -- */
      /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
      /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
      /* November 2013 */
      /* .. Scalar Arguments .. */
      /* .. */
      /* .. Array Arguments .. */
      /* .. */
      /* ===================================================================== */
      /* .. Parameters .. */
      /* .. */
      /* .. Local Scalars .. */
      /* .. */
      /* .. External Functions .. */
      /* .. */
      /* .. External Subroutines .. */
      /* .. */
      /* .. Intrinsic Functions .. */
      /* .. */
      /* .. Statement Functions .. */
      /* .. */
      /* .. Statement Function definitions .. */
      /* .. */
      /* .. Executable Statements .. */
      /* Test the input parameters. */
      /* Parameter adjustments */
      a_dim1 = *lda;
      a_offset = 1 + a_dim1;
      a -= a_offset;
      --ipiv;
      /* Function Body */
      *info = 0;
      upper = lsame_(uplo, "U");
      if (! upper && ! lsame_(uplo, "L"))
      {
          *info = -1;
      }
      else if (*n < 0)
      {
          *info = -2;
      }
      else if (*lda < max(1,*n))
      {
          *info = -4;
      }
      if (*info != 0)
      {
          i__1 = -(*info);
          xerbla_("ZSYTF2", &i__1);
          return 0;
      }
      /* Initialize ALPHA for use in choosing pivot block size. */
      alpha = (sqrt(17.) + 1.) / 8.;
      if (upper)
      {
          /* Factorize A as U*D*U**T using the upper triangle of A */
          /* K is the main loop index, decreasing from N to 1 in steps of */
          /* 1 or 2 */
          k = *n;
  L10: /* If K < 1, exit from loop */
          if (k < 1)
          {
              goto L70;
          }
          kstep = 1;
          /* Determine rows and columns to be interchanged and whether */
          /* a 1-by-1 or 2-by-2 pivot block will be used */
          i__1 = k + k * a_dim1;
          absakk = (d__1 = a[i__1].r, abs(d__1)) + (d__2 = d_imag(&a[k + k * a_dim1]), abs(d__2));
          /* IMAX is the row-index of the largest off-diagonal element in */
          /* column K, and COLMAX is its absolute value. */
          /* Determine both COLMAX and IMAX. */
          if (k > 1)
          {
              i__1 = k - 1;
              imax = izamax_(&i__1, &a[k * a_dim1 + 1], &c__1);
              i__1 = imax + k * a_dim1;
              colmax = (d__1 = a[i__1].r, abs(d__1)) + (d__2 = d_imag(&a[imax + k * a_dim1]), abs(d__2));
          }
          else
          {
              colmax = 0.;
          }
          if (max(absakk,colmax) == 0. || disnan_(&absakk))
          {
              /* Column K is zero or underflow, or contains a NaN: */
              /* set INFO and continue */
              if (*info == 0)
              {
                  *info = k;
              }
              kp = k;
          }
          else
          {
              if (absakk >= alpha * colmax)
              {
                  /* no interchange, use 1-by-1 pivot block */
                  kp = k;
              }
              else
              {
                  /* JMAX is the column-index of the largest off-diagonal */
                  /* element in row IMAX, and ROWMAX is its absolute value */
                  i__1 = k - imax;
                  jmax = imax + izamax_(&i__1, &a[imax + (imax + 1) * a_dim1], lda);
                  i__1 = imax + jmax * a_dim1;
                  rowmax = (d__1 = a[i__1].r, abs(d__1)) + (d__2 = d_imag(&a[ imax + jmax * a_dim1]), abs(d__2));
                  if (imax > 1)
                  {
                      i__1 = imax - 1;
                      jmax = izamax_(&i__1, &a[imax * a_dim1 + 1], &c__1);
                      /* Computing MAX */
                      i__1 = jmax + imax * a_dim1;
                      d__3 = rowmax;
                      d__4 = (d__1 = a[i__1].r, abs(d__1)) + ( d__2 = d_imag(&a[jmax + imax * a_dim1]), abs(d__2) ); // , expr subst
                      rowmax = max(d__3,d__4);
                  }
                  if (absakk >= alpha * colmax * (colmax / rowmax))
                  {
                      /* no interchange, use 1-by-1 pivot block */
                      kp = k;
                  }
                  else /* if(complicated condition) */
                  {
                      i__1 = imax + imax * a_dim1;
                      if ((d__1 = a[i__1].r, abs(d__1)) + (d__2 = d_imag(&a[ imax + imax * a_dim1]), abs(d__2)) >= alpha * rowmax)
                      {
                          /* interchange rows and columns K and IMAX, use 1-by-1 */
                          /* pivot block */
                          kp = imax;
                      }
                      else
                      {
                          /* interchange rows and columns K-1 and IMAX, use 2-by-2 */
                          /* pivot block */
                          kp = imax;
                          kstep = 2;
                      }
                  }
              }
              kk = k - kstep + 1;
              if (kp != kk)
              {
                  /* Interchange rows and columns KK and KP in the leading */
                  /* submatrix A(1:k,1:k) */
                  i__1 = kp - 1;
                  zswap_(&i__1, &a[kk * a_dim1 + 1], &c__1, &a[kp * a_dim1 + 1], &c__1);
                  i__1 = kk - kp - 1;
                  zswap_(&i__1, &a[kp + 1 + kk * a_dim1], &c__1, &a[kp + (kp + 1) * a_dim1], lda);
                  i__1 = kk + kk * a_dim1;
                  t.r = a[i__1].r;
                  t.i = a[i__1].i; // , expr subst
                  i__1 = kk + kk * a_dim1;
                  i__2 = kp + kp * a_dim1;
                  a[i__1].r = a[i__2].r;
                  a[i__1].i = a[i__2].i; // , expr subst
                  i__1 = kp + kp * a_dim1;
                  a[i__1].r = t.r;
                  a[i__1].i = t.i; // , expr subst
                  if (kstep == 2)
                  {
                      i__1 = k - 1 + k * a_dim1;
                      t.r = a[i__1].r;
                      t.i = a[i__1].i; // , expr subst
                      i__1 = k - 1 + k * a_dim1;
                      i__2 = kp + k * a_dim1;
                      a[i__1].r = a[i__2].r;
                      a[i__1].i = a[i__2].i; // , expr subst
                      i__1 = kp + k * a_dim1;
                      a[i__1].r = t.r;
                      a[i__1].i = t.i; // , expr subst
                  }
              }
              /* Update the leading submatrix */
              if (kstep == 1)
              {
                  /* 1-by-1 pivot block D(k): column k now holds */
                  /* W(k) = U(k)*D(k) */
                  /* where U(k) is the k-th column of U */
                  /* Perform a rank-1 update of A(1:k-1,1:k-1) as */
                  /* A := A - U(k)*D(k)*U(k)**T = A - W(k)*1/D(k)*W(k)**T */
                  z_div(&z__1, &c_b1, &a[k + k * a_dim1]);
                  r1.r = z__1.r;
                  r1.i = z__1.i; // , expr subst
                  i__1 = k - 1;
                  z__1.r = -r1.r;
                  z__1.i = -r1.i; // , expr subst
                  zsyr_(uplo, &i__1, &z__1, &a[k * a_dim1 + 1], &c__1, &a[ a_offset], lda);
                  /* Store U(k) in column k */
                  i__1 = k - 1;
                  zscal_(&i__1, &r1, &a[k * a_dim1 + 1], &c__1);
              }
              else
              {
                  /* 2-by-2 pivot block D(k): columns k and k-1 now hold */
                  /* ( W(k-1) W(k) ) = ( U(k-1) U(k) )*D(k) */
                  /* where U(k) and U(k-1) are the k-th and (k-1)-th columns */
                  /* of U */
                  /* Perform a rank-2 update of A(1:k-2,1:k-2) as */
                  /* A := A - ( U(k-1) U(k) )*D(k)*( U(k-1) U(k) )**T */
                  /* = A - ( W(k-1) W(k) )*inv(D(k))*( W(k-1) W(k) )**T */
                  if (k > 2)
                  {
                      i__1 = k - 1 + k * a_dim1;
                      d12.r = a[i__1].r;
                      d12.i = a[i__1].i; // , expr subst
                      z_div(&z__1, &a[k - 1 + (k - 1) * a_dim1], &d12);
                      d22.r = z__1.r;
                      d22.i = z__1.i; // , expr subst
                      z_div(&z__1, &a[k + k * a_dim1], &d12);
                      d11.r = z__1.r;
                      d11.i = z__1.i; // , expr subst
                      z__3.r = d11.r * d22.r - d11.i * d22.i;
                      z__3.i = d11.r * d22.i + d11.i * d22.r; // , expr subst
                      z__2.r = z__3.r - 1.;
                      z__2.i = z__3.i - 0.; // , expr subst
                      z_div(&z__1, &c_b1, &z__2);
                      t.r = z__1.r;
                      t.i = z__1.i; // , expr subst
                      z_div(&z__1, &t, &d12);
                      d12.r = z__1.r;
                      d12.i = z__1.i; // , expr subst
                      for (j = k - 2;
                              j >= 1;
                              --j)
                      {
                          i__1 = j + (k - 1) * a_dim1;
                          z__3.r = d11.r * a[i__1].r - d11.i * a[i__1].i;
                          z__3.i = d11.r * a[i__1].i + d11.i * a[i__1] .r; // , expr subst
                          i__2 = j + k * a_dim1;
                          z__2.r = z__3.r - a[i__2].r;
                          z__2.i = z__3.i - a[i__2] .i; // , expr subst
                          z__1.r = d12.r * z__2.r - d12.i * z__2.i;
                          z__1.i = d12.r * z__2.i + d12.i * z__2.r; // , expr subst
                          wkm1.r = z__1.r;
                          wkm1.i = z__1.i; // , expr subst
                          i__1 = j + k * a_dim1;
                          z__3.r = d22.r * a[i__1].r - d22.i * a[i__1].i;
                          z__3.i = d22.r * a[i__1].i + d22.i * a[i__1] .r; // , expr subst
                          i__2 = j + (k - 1) * a_dim1;
                          z__2.r = z__3.r - a[i__2].r;
                          z__2.i = z__3.i - a[i__2] .i; // , expr subst
                          z__1.r = d12.r * z__2.r - d12.i * z__2.i;
                          z__1.i = d12.r * z__2.i + d12.i * z__2.r; // , expr subst
                          wk.r = z__1.r;
                          wk.i = z__1.i; // , expr subst
                          for (i__ = j;
                                  i__ >= 1;
                                  --i__)
                          {
                              i__1 = i__ + j * a_dim1;
                              i__2 = i__ + j * a_dim1;
                              i__3 = i__ + k * a_dim1;
                              z__3.r = a[i__3].r * wk.r - a[i__3].i * wk.i;
                              z__3.i = a[i__3].r * wk.i + a[i__3].i * wk.r; // , expr subst
                              z__2.r = a[i__2].r - z__3.r;
                              z__2.i = a[i__2].i - z__3.i; // , expr subst
                              i__4 = i__ + (k - 1) * a_dim1;
                              z__4.r = a[i__4].r * wkm1.r - a[i__4].i * wkm1.i;
                              z__4.i = a[i__4].r * wkm1.i + a[i__4].i * wkm1.r; // , expr subst
                              z__1.r = z__2.r - z__4.r;
                              z__1.i = z__2.i - z__4.i; // , expr subst
                              a[i__1].r = z__1.r;
                              a[i__1].i = z__1.i; // , expr subst
                              /* L20: */
                          }
                          i__1 = j + k * a_dim1;
                          a[i__1].r = wk.r;
                          a[i__1].i = wk.i; // , expr subst
                          i__1 = j + (k - 1) * a_dim1;
                          a[i__1].r = wkm1.r;
                          a[i__1].i = wkm1.i; // , expr subst
                          /* L30: */
                      }
                  }
              }
          }
          /* Store details of the interchanges in IPIV */
          if (kstep == 1)
          {
              ipiv[k] = kp;
          }
          else
          {
              ipiv[k] = -kp;
              ipiv[k - 1] = -kp;
          }
          /* Decrease K and return to the start of the main loop */
          k -= kstep;
          goto L10;
      }
      else
      {
          /* Factorize A as L*D*L**T using the lower triangle of A */
          /* K is the main loop index, increasing from 1 to N in steps of */
          /* 1 or 2 */
          k = 1;
  L40: /* If K > N, exit from loop */
          if (k > *n)
          {
              goto L70;
          }
          kstep = 1;
          /* Determine rows and columns to be interchanged and whether */
          /* a 1-by-1 or 2-by-2 pivot block will be used */
          i__1 = k + k * a_dim1;
          absakk = (d__1 = a[i__1].r, abs(d__1)) + (d__2 = d_imag(&a[k + k * a_dim1]), abs(d__2));
          /* IMAX is the row-index of the largest off-diagonal element in */
          /* column K, and COLMAX is its absolute value. */
          /* Determine both COLMAX and IMAX. */
          if (k < *n)
          {
              i__1 = *n - k;
              imax = k + izamax_(&i__1, &a[k + 1 + k * a_dim1], &c__1);
              i__1 = imax + k * a_dim1;
              colmax = (d__1 = a[i__1].r, abs(d__1)) + (d__2 = d_imag(&a[imax + k * a_dim1]), abs(d__2));
          }
          else
          {
              colmax = 0.;
          }
          if (max(absakk,colmax) == 0. || disnan_(&absakk))
          {
              /* Column K is zero or underflow, or contains a NaN: */
              /* set INFO and continue */
              if (*info == 0)
              {
                  *info = k;
              }
              kp = k;
          }
          else
          {
              if (absakk >= alpha * colmax)
              {
                  /* no interchange, use 1-by-1 pivot block */
                  kp = k;
              }
              else
              {
                  /* JMAX is the column-index of the largest off-diagonal */
                  /* element in row IMAX, and ROWMAX is its absolute value */
                  i__1 = imax - k;
                  jmax = k - 1 + izamax_(&i__1, &a[imax + k * a_dim1], lda);
                  i__1 = imax + jmax * a_dim1;
                  rowmax = (d__1 = a[i__1].r, abs(d__1)) + (d__2 = d_imag(&a[ imax + jmax * a_dim1]), abs(d__2));
                  if (imax < *n)
                  {
                      i__1 = *n - imax;
                      jmax = imax + izamax_(&i__1, &a[imax + 1 + imax * a_dim1], &c__1);
                      /* Computing MAX */
                      i__1 = jmax + imax * a_dim1;
                      d__3 = rowmax;
                      d__4 = (d__1 = a[i__1].r, abs(d__1)) + ( d__2 = d_imag(&a[jmax + imax * a_dim1]), abs(d__2) ); // , expr subst
                      rowmax = max(d__3,d__4);
                  }
                  if (absakk >= alpha * colmax * (colmax / rowmax))
                  {
                      /* no interchange, use 1-by-1 pivot block */
                      kp = k;
                  }
                  else /* if(complicated condition) */
                  {
                      i__1 = imax + imax * a_dim1;
                      if ((d__1 = a[i__1].r, abs(d__1)) + (d__2 = d_imag(&a[ imax + imax * a_dim1]), abs(d__2)) >= alpha * rowmax)
                      {
                          /* interchange rows and columns K and IMAX, use 1-by-1 */
                          /* pivot block */
                          kp = imax;
                      }
                      else
                      {
                          /* interchange rows and columns K+1 and IMAX, use 2-by-2 */
                          /* pivot block */
                          kp = imax;
                          kstep = 2;
                      }
                  }
              }
              kk = k + kstep - 1;
              if (kp != kk)
              {
                  /* Interchange rows and columns KK and KP in the trailing */
                  /* submatrix A(k:n,k:n) */
                  if (kp < *n)
                  {
                      i__1 = *n - kp;
                      zswap_(&i__1, &a[kp + 1 + kk * a_dim1], &c__1, &a[kp + 1 + kp * a_dim1], &c__1);
                  }
                  i__1 = kp - kk - 1;
                  zswap_(&i__1, &a[kk + 1 + kk * a_dim1], &c__1, &a[kp + (kk + 1) * a_dim1], lda);
                  i__1 = kk + kk * a_dim1;
                  t.r = a[i__1].r;
                  t.i = a[i__1].i; // , expr subst
                  i__1 = kk + kk * a_dim1;
                  i__2 = kp + kp * a_dim1;
                  a[i__1].r = a[i__2].r;
                  a[i__1].i = a[i__2].i; // , expr subst
                  i__1 = kp + kp * a_dim1;
                  a[i__1].r = t.r;
                  a[i__1].i = t.i; // , expr subst
                  if (kstep == 2)
                  {
                      i__1 = k + 1 + k * a_dim1;
                      t.r = a[i__1].r;
                      t.i = a[i__1].i; // , expr subst
                      i__1 = k + 1 + k * a_dim1;
                      i__2 = kp + k * a_dim1;
                      a[i__1].r = a[i__2].r;
                      a[i__1].i = a[i__2].i; // , expr subst
                      i__1 = kp + k * a_dim1;
                      a[i__1].r = t.r;
                      a[i__1].i = t.i; // , expr subst
                  }
              }
              /* Update the trailing submatrix */
              if (kstep == 1)
              {
                  /* 1-by-1 pivot block D(k): column k now holds */
                  /* W(k) = L(k)*D(k) */
                  /* where L(k) is the k-th column of L */
                  if (k < *n)
                  {
                      /* Perform a rank-1 update of A(k+1:n,k+1:n) as */
                      /* A := A - L(k)*D(k)*L(k)**T = A - W(k)*(1/D(k))*W(k)**T */
                      z_div(&z__1, &c_b1, &a[k + k * a_dim1]);
                      r1.r = z__1.r;
                      r1.i = z__1.i; // , expr subst
                      i__1 = *n - k;
                      z__1.r = -r1.r;
                      z__1.i = -r1.i; // , expr subst
                      zsyr_(uplo, &i__1, &z__1, &a[k + 1 + k * a_dim1], &c__1, & a[k + 1 + (k + 1) * a_dim1], lda);
                      /* Store L(k) in column K */
                      i__1 = *n - k;
                      zscal_(&i__1, &r1, &a[k + 1 + k * a_dim1], &c__1);
                  }
              }
              else
              {
                  /* 2-by-2 pivot block D(k) */
                  if (k < *n - 1)
                  {
                      /* Perform a rank-2 update of A(k+2:n,k+2:n) as */
                      /* A := A - ( L(k) L(k+1) )*D(k)*( L(k) L(k+1) )**T */
                      /* = A - ( W(k) W(k+1) )*inv(D(k))*( W(k) W(k+1) )**T */
                      /* where L(k) and L(k+1) are the k-th and (k+1)-th */
                      /* columns of L */
                      i__1 = k + 1 + k * a_dim1;
                      d21.r = a[i__1].r;
                      d21.i = a[i__1].i; // , expr subst
                      z_div(&z__1, &a[k + 1 + (k + 1) * a_dim1], &d21);
                      d11.r = z__1.r;
                      d11.i = z__1.i; // , expr subst
                      z_div(&z__1, &a[k + k * a_dim1], &d21);
                      d22.r = z__1.r;
                      d22.i = z__1.i; // , expr subst
                      z__3.r = d11.r * d22.r - d11.i * d22.i;
                      z__3.i = d11.r * d22.i + d11.i * d22.r; // , expr subst
                      z__2.r = z__3.r - 1.;
                      z__2.i = z__3.i - 0.; // , expr subst
                      z_div(&z__1, &c_b1, &z__2);
                      t.r = z__1.r;
                      t.i = z__1.i; // , expr subst
                      z_div(&z__1, &t, &d21);
                      d21.r = z__1.r;
                      d21.i = z__1.i; // , expr subst
                      i__1 = *n;
                      for (j = k + 2;
                              j <= i__1;
                              ++j)
                      {
                          i__2 = j + k * a_dim1;
                          z__3.r = d11.r * a[i__2].r - d11.i * a[i__2].i;
                          z__3.i = d11.r * a[i__2].i + d11.i * a[i__2] .r; // , expr subst
                          i__3 = j + (k + 1) * a_dim1;
                          z__2.r = z__3.r - a[i__3].r;
                          z__2.i = z__3.i - a[i__3] .i; // , expr subst
                          z__1.r = d21.r * z__2.r - d21.i * z__2.i;
                          z__1.i = d21.r * z__2.i + d21.i * z__2.r; // , expr subst
                          wk.r = z__1.r;
                          wk.i = z__1.i; // , expr subst
                          i__2 = j + (k + 1) * a_dim1;
                          z__3.r = d22.r * a[i__2].r - d22.i * a[i__2].i;
                          z__3.i = d22.r * a[i__2].i + d22.i * a[i__2] .r; // , expr subst
                          i__3 = j + k * a_dim1;
                          z__2.r = z__3.r - a[i__3].r;
                          z__2.i = z__3.i - a[i__3] .i; // , expr subst
                          z__1.r = d21.r * z__2.r - d21.i * z__2.i;
                          z__1.i = d21.r * z__2.i + d21.i * z__2.r; // , expr subst
                          wkp1.r = z__1.r;
                          wkp1.i = z__1.i; // , expr subst
                          i__2 = *n;
                          for (i__ = j;
                                  i__ <= i__2;
                                  ++i__)
                          {
                              i__3 = i__ + j * a_dim1;
                              i__4 = i__ + j * a_dim1;
                              i__5 = i__ + k * a_dim1;
                              z__3.r = a[i__5].r * wk.r - a[i__5].i * wk.i;
                              z__3.i = a[i__5].r * wk.i + a[i__5].i * wk.r; // , expr subst
                              z__2.r = a[i__4].r - z__3.r;
                              z__2.i = a[i__4].i - z__3.i; // , expr subst
                              i__6 = i__ + (k + 1) * a_dim1;
                              z__4.r = a[i__6].r * wkp1.r - a[i__6].i * wkp1.i;
                              z__4.i = a[i__6].r * wkp1.i + a[i__6].i * wkp1.r; // , expr subst
                              z__1.r = z__2.r - z__4.r;
                              z__1.i = z__2.i - z__4.i; // , expr subst
                              a[i__3].r = z__1.r;
                              a[i__3].i = z__1.i; // , expr subst
                              /* L50: */
                          }
                          i__2 = j + k * a_dim1;
                          a[i__2].r = wk.r;
                          a[i__2].i = wk.i; // , expr subst
                          i__2 = j + (k + 1) * a_dim1;
                          a[i__2].r = wkp1.r;
                          a[i__2].i = wkp1.i; // , expr subst
                          /* L60: */
                      }
                  }
              }
          }
          /* Store details of the interchanges in IPIV */
          if (kstep == 1)
          {
              ipiv[k] = kp;
          }
          else
          {
              ipiv[k] = -kp;
              ipiv[k + 1] = -kp;
          }
          /* Increase K and return to the start of the main loop */
          k += kstep;
          goto L40;
      }
  L70:
      return 0;
      /* End of ZSYTF2 */
  }
  /* zsytf2_ */
  