text: /* slatrs.f -- translated by f2c (version 20061008).
     You must link the resulting object file with libf2c:
  	on Microsoft Windows system, link with libf2c.lib;
  	on Linux or Unix systems, link with .../path/to/libf2c.a -lm
  	or, if you install libf2c.a in a standard place, with -lf2c -lm
  	-- in that order, at the end of the command line, as in
  		cc *.o -lf2c -lm
  	Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
  
  		http://www.netlib.org/f2c/libf2c.zip
  */
  
  #include "f2c.h"
  #include "blaswrap.h"
  
  /* Table of constant values */
  
  static integer c__1 = 1;
  static real c_b36 = .5f;
  
  /* Subroutine */ int slatrs_(char *uplo, char *trans, char *diag, char *
  	normin, integer *n, real *a, integer *lda, real *x, real *scale, real 
  	*cnorm, integer *info)
  {
      /* System generated locals */
      integer a_dim1, a_offset, i__1, i__2, i__3;
      real r__1, r__2, r__3;
  
      /* Local variables */
      integer i__, j;
      real xj, rec, tjj;
      integer jinc;
      real xbnd;
      integer imax;
      real tmax, tjjs;
      extern doublereal sdot_(integer *, real *, integer *, real *, integer *);
      real xmax, grow, sumj;
      extern logical lsame_(char *, char *);
      extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *);
      real tscal, uscal;
      integer jlast;
      extern doublereal sasum_(integer *, real *, integer *);
      logical upper;
      extern /* Subroutine */ int saxpy_(integer *, real *, real *, integer *, 
  	    real *, integer *), strsv_(char *, char *, char *, integer *, 
  	    real *, integer *, real *, integer *);
      extern doublereal slamch_(char *);
      extern /* Subroutine */ int xerbla_(char *, integer *);
      real bignum;
      extern integer isamax_(integer *, real *, integer *);
      logical notran;
      integer jfirst;
      real smlnum;
      logical nounit;
  
  
  /*  -- LAPACK auxiliary routine (version 3.2) -- */
  /*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
  /*     November 2006 */
  
  /*     .. Scalar Arguments .. */
  /*     .. */
  /*     .. Array Arguments .. */
  /*     .. */
  
  /*  Purpose */
  /*  ======= */
  
  /*  SLATRS solves one of the triangular systems */
  
  /*     A *x = s*b  or  A'*x = s*b */
  
  /*  with scaling to prevent overflow.  Here A is an upper or lower */
  /*  triangular matrix, A' denotes the transpose of A, x and b are */
  /*  n-element vectors, and s is a scaling factor, usually less than */
  /*  or equal to 1, chosen so that the components of x will be less than */
  /*  the overflow threshold.  If the unscaled problem will not cause */
  /*  overflow, the Level 2 BLAS routine STRSV is called.  If the matrix A */
  /*  is singular (A(j,j) = 0 for some j), then s is set to 0 and a */
  /*  non-trivial solution to A*x = 0 is returned. */
  
  /*  Arguments */
  /*  ========= */
  
  /*  UPLO    (input) CHARACTER*1 */
  /*          Specifies whether the matrix A is upper or lower triangular. */
  /*          = 'U':  Upper triangular */
  /*          = 'L':  Lower triangular */
  
  /*  TRANS   (input) CHARACTER*1 */
  /*          Specifies the operation applied to A. */
  /*          = 'N':  Solve A * x = s*b  (No transpose) */
  /*          = 'T':  Solve A'* x = s*b  (Transpose) */
  /*          = 'C':  Solve A'* x = s*b  (Conjugate transpose = Transpose) */
  
  /*  DIAG    (input) CHARACTER*1 */
  /*          Specifies whether or not the matrix A is unit triangular. */
  /*          = 'N':  Non-unit triangular */
  /*          = 'U':  Unit triangular */
  
  /*  NORMIN  (input) CHARACTER*1 */
  /*          Specifies whether CNORM has been set or not. */
  /*          = 'Y':  CNORM contains the column norms on entry */
  /*          = 'N':  CNORM is not set on entry.  On exit, the norms will */
  /*                  be computed and stored in CNORM. */
  
  /*  N       (input) INTEGER */
  /*          The order of the matrix A.  N >= 0. */
  
  /*  A       (input) REAL array, dimension (LDA,N) */
  /*          The triangular matrix A.  If UPLO = 'U', the leading n by n */
  /*          upper triangular part of the array A contains the upper */
  /*          triangular matrix, and the strictly lower triangular part of */
  /*          A is not referenced.  If UPLO = 'L', the leading n by n lower */
  /*          triangular part of the array A contains the lower triangular */
  /*          matrix, and the strictly upper triangular part of A is not */
  /*          referenced.  If DIAG = 'U', the diagonal elements of A are */
  /*          also not referenced and are assumed to be 1. */
  
  /*  LDA     (input) INTEGER */
  /*          The leading dimension of the array A.  LDA >= max (1,N). */
  
  /*  X       (input/output) REAL array, dimension (N) */
  /*          On entry, the right hand side b of the triangular system. */
  /*          On exit, X is overwritten by the solution vector x. */
  
  /*  SCALE   (output) REAL */
  /*          The scaling factor s for the triangular system */
  /*             A * x = s*b  or  A'* x = s*b. */
  /*          If SCALE = 0, the matrix A is singular or badly scaled, and */
  /*          the vector x is an exact or approximate solution to A*x = 0. */
  
  /*  CNORM   (input or output) REAL array, dimension (N) */
  
  /*          If NORMIN = 'Y', CNORM is an input argument and CNORM(j) */
  /*          contains the norm of the off-diagonal part of the j-th column */
  /*          of A.  If TRANS = 'N', CNORM(j) must be greater than or equal */
  /*          to the infinity-norm, and if TRANS = 'T' or 'C', CNORM(j) */
  /*          must be greater than or equal to the 1-norm. */
  
  /*          If NORMIN = 'N', CNORM is an output argument and CNORM(j) */
  /*          returns the 1-norm of the offdiagonal part of the j-th column */
  /*          of A. */
  
  /*  INFO    (output) INTEGER */
  /*          = 0:  successful exit */
  /*          < 0:  if INFO = -k, the k-th argument had an illegal value */
  
  /*  Further Details */
  /*  ======= ======= */
  
  /*  A rough bound on x is computed; if that is less than overflow, STRSV */
  /*  is called, otherwise, specific code is used which checks for possible */
  /*  overflow or divide-by-zero at every operation. */
  
  /*  A columnwise scheme is used for solving A*x = b.  The basic algorithm */
  /*  if A is lower triangular is */
  
  /*       x[1:n] := b[1:n] */
  /*       for j = 1, ..., n */
  /*            x(j) := x(j) / A(j,j) */
  /*            x[j+1:n] := x[j+1:n] - x(j) * A[j+1:n,j] */
  /*       end */
  
  /*  Define bounds on the components of x after j iterations of the loop: */
  /*     M(j) = bound on x[1:j] */
  /*     G(j) = bound on x[j+1:n] */
  /*  Initially, let M(0) = 0 and G(0) = max{x(i), i=1,...,n}. */
  
  /*  Then for iteration j+1 we have */
  /*     M(j+1) <= G(j) / | A(j+1,j+1) | */
  /*     G(j+1) <= G(j) + M(j+1) * | A[j+2:n,j+1] | */
  /*            <= G(j) ( 1 + CNORM(j+1) / | A(j+1,j+1) | ) */
  
  /*  where CNORM(j+1) is greater than or equal to the infinity-norm of */
  /*  column j+1 of A, not counting the diagonal.  Hence */
  
  /*     G(j) <= G(0) product ( 1 + CNORM(i) / | A(i,i) | ) */
  /*                  1<=i<=j */
  /*  and */
  
  /*     |x(j)| <= ( G(0) / |A(j,j)| ) product ( 1 + CNORM(i) / |A(i,i)| ) */
  /*                                   1<=i< j */
  
  /*  Since |x(j)| <= M(j), we use the Level 2 BLAS routine STRSV if the */
  /*  reciprocal of the largest M(j), j=1,..,n, is larger than */
  /*  max(underflow, 1/overflow). */
  
  /*  The bound on x(j) is also used to determine when a step in the */
  /*  columnwise method can be performed without fear of overflow.  If */
  /*  the computed bound is greater than a large constant, x is scaled to */
  /*  prevent overflow, but if the bound overflows, x is set to 0, x(j) to */
  /*  1, and scale to 0, and a non-trivial solution to A*x = 0 is found. */
  
  /*  Similarly, a row-wise scheme is used to solve A'*x = b.  The basic */
  /*  algorithm for A upper triangular is */
  
  /*       for j = 1, ..., n */
  /*            x(j) := ( b(j) - A[1:j-1,j]' * x[1:j-1] ) / A(j,j) */
  /*       end */
  
  /*  We simultaneously compute two bounds */
  /*       G(j) = bound on ( b(i) - A[1:i-1,i]' * x[1:i-1] ), 1<=i<=j */
  /*       M(j) = bound on x(i), 1<=i<=j */
  
  /*  The initial values are G(0) = 0, M(0) = max{b(i), i=1,..,n}, and we */
  /*  add the constraint G(j) >= G(j-1) and M(j) >= M(j-1) for j >= 1. */
  /*  Then the bound on x(j) is */
  
  /*       M(j) <= M(j-1) * ( 1 + CNORM(j) ) / | A(j,j) | */
  
  /*            <= M(0) * product ( ( 1 + CNORM(i) ) / |A(i,i)| ) */
  /*                      1<=i<=j */
  
  /*  and we can safely call STRSV if 1/M(n) and 1/G(n) are both greater */
  /*  than max(underflow, 1/overflow). */
  
  /*  ===================================================================== */
  
  /*     .. Parameters .. */
  /*     .. */
  /*     .. Local Scalars .. */
  /*     .. */
  /*     .. External Functions .. */
  /*     .. */
  /*     .. External Subroutines .. */
  /*     .. */
  /*     .. Intrinsic Functions .. */
  /*     .. */
  /*     .. Executable Statements .. */
  
      /* Parameter adjustments */
      a_dim1 = *lda;
      a_offset = 1 + a_dim1;
      a -= a_offset;
      --x;
      --cnorm;
  
      /* Function Body */
      *info = 0;
      upper = lsame_(uplo, "U");
      notran = lsame_(trans, "N");
      nounit = lsame_(diag, "N");
  
  /*     Test the input parameters. */
  
      if (! upper && ! lsame_(uplo, "L")) {
  	*info = -1;
      } else if (! notran && ! lsame_(trans, "T") && ! 
  	    lsame_(trans, "C")) {
  	*info = -2;
      } else if (! nounit && ! lsame_(diag, "U")) {
  	*info = -3;
      } else if (! lsame_(normin, "Y") && ! lsame_(normin, 
  	     "N")) {
  	*info = -4;
      } else if (*n < 0) {
  	*info = -5;
      } else if (*lda < max(1,*n)) {
  	*info = -7;
      }
      if (*info != 0) {
  	i__1 = -(*info);
  	xerbla_("SLATRS", &i__1);
  	return 0;
      }
  
  /*     Quick return if possible */
  
      if (*n == 0) {
  	return 0;
      }
  
  /*     Determine machine dependent parameters to control overflow. */
  
      smlnum = slamch_("Safe minimum") / slamch_("Precision");
      bignum = 1.f / smlnum;
      *scale = 1.f;
  
      if (lsame_(normin, "N")) {
  
  /*        Compute the 1-norm of each column, not including the diagonal. */
  
  	if (upper) {
  
  /*           A is upper triangular. */
  
  	    i__1 = *n;
  	    for (j = 1; j <= i__1; ++j) {
  		i__2 = j - 1;
  		cnorm[j] = sasum_(&i__2, &a[j * a_dim1 + 1], &c__1);
  /* L10: */
  	    }
  	} else {
  
  /*           A is lower triangular. */
  
  	    i__1 = *n - 1;
  	    for (j = 1; j <= i__1; ++j) {
  		i__2 = *n - j;
  		cnorm[j] = sasum_(&i__2, &a[j + 1 + j * a_dim1], &c__1);
  /* L20: */
  	    }
  	    cnorm[*n] = 0.f;
  	}
      }
  
  /*     Scale the column norms by TSCAL if the maximum element in CNORM is */
  /*     greater than BIGNUM. */
  
      imax = isamax_(n, &cnorm[1], &c__1);
      tmax = cnorm[imax];
      if (tmax <= bignum) {
  	tscal = 1.f;
      } else {
  	tscal = 1.f / (smlnum * tmax);
  	sscal_(n, &tscal, &cnorm[1], &c__1);
      }
  
  /*     Compute a bound on the computed solution vector to see if the */
  /*     Level 2 BLAS routine STRSV can be used. */
  
      j = isamax_(n, &x[1], &c__1);
      xmax = (r__1 = x[j], dabs(r__1));
      xbnd = xmax;
      if (notran) {
  
  /*        Compute the growth in A * x = b. */
  
  	if (upper) {
  	    jfirst = *n;
  	    jlast = 1;
  	    jinc = -1;
  	} else {
  	    jfirst = 1;
  	    jlast = *n;
  	    jinc = 1;
  	}
  
  	if (tscal != 1.f) {
  	    grow = 0.f;
  	    goto L50;
  	}
  
  	if (nounit) {
  
  /*           A is non-unit triangular. */
  
  /*           Compute GROW = 1/G(j) and XBND = 1/M(j). */
  /*           Initially, G(0) = max{x(i), i=1,...,n}. */
  
  	    grow = 1.f / dmax(xbnd,smlnum);
  	    xbnd = grow;
  	    i__1 = jlast;
  	    i__2 = jinc;
  	    for (j = jfirst; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) {
  
  /*              Exit the loop if the growth factor is too small. */
  
  		if (grow <= smlnum) {
  		    goto L50;
  		}
  
  /*              M(j) = G(j-1) / abs(A(j,j)) */
  
  		tjj = (r__1 = a[j + j * a_dim1], dabs(r__1));
  /* Computing MIN */
  		r__1 = xbnd, r__2 = dmin(1.f,tjj) * grow;
  		xbnd = dmin(r__1,r__2);
  		if (tjj + cnorm[j] >= smlnum) {
  
  /*                 G(j) = G(j-1)*( 1 + CNORM(j) / abs(A(j,j)) ) */
  
  		    grow *= tjj / (tjj + cnorm[j]);
  		} else {
  
  /*                 G(j) could overflow, set GROW to 0. */
  
  		    grow = 0.f;
  		}
  /* L30: */
  	    }
  	    grow = xbnd;
  	} else {
  
  /*           A is unit triangular. */
  
  /*           Compute GROW = 1/G(j), where G(0) = max{x(i), i=1,...,n}. */
  
  /* Computing MIN */
  	    r__1 = 1.f, r__2 = 1.f / dmax(xbnd,smlnum);
  	    grow = dmin(r__1,r__2);
  	    i__2 = jlast;
  	    i__1 = jinc;
  	    for (j = jfirst; i__1 < 0 ? j >= i__2 : j <= i__2; j += i__1) {
  
  /*              Exit the loop if the growth factor is too small. */
  
  		if (grow <= smlnum) {
  		    goto L50;
  		}
  
  /*              G(j) = G(j-1)*( 1 + CNORM(j) ) */
  
  		grow *= 1.f / (cnorm[j] + 1.f);
  /* L40: */
  	    }
  	}
  L50:
  
  	;
      } else {
  
  /*        Compute the growth in A' * x = b. */
  
  	if (upper) {
  	    jfirst = 1;
  	    jlast = *n;
  	    jinc = 1;
  	} else {
  	    jfirst = *n;
  	    jlast = 1;
  	    jinc = -1;
  	}
  
  	if (tscal != 1.f) {
  	    grow = 0.f;
  	    goto L80;
  	}
  
  	if (nounit) {
  
  /*           A is non-unit triangular. */
  
  /*           Compute GROW = 1/G(j) and XBND = 1/M(j). */
  /*           Initially, M(0) = max{x(i), i=1,...,n}. */
  
  	    grow = 1.f / dmax(xbnd,smlnum);
  	    xbnd = grow;
  	    i__1 = jlast;
  	    i__2 = jinc;
  	    for (j = jfirst; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) {
  
  /*              Exit the loop if the growth factor is too small. */
  
  		if (grow <= smlnum) {
  		    goto L80;
  		}
  
  /*              G(j) = max( G(j-1), M(j-1)*( 1 + CNORM(j) ) ) */
  
  		xj = cnorm[j] + 1.f;
  /* Computing MIN */
  		r__1 = grow, r__2 = xbnd / xj;
  		grow = dmin(r__1,r__2);
  
  /*              M(j) = M(j-1)*( 1 + CNORM(j) ) / abs(A(j,j)) */
  
  		tjj = (r__1 = a[j + j * a_dim1], dabs(r__1));
  		if (xj > tjj) {
  		    xbnd *= tjj / xj;
  		}
  /* L60: */
  	    }
  	    grow = dmin(grow,xbnd);
  	} else {
  
  /*           A is unit triangular. */
  
  /*           Compute GROW = 1/G(j), where G(0) = max{x(i), i=1,...,n}. */
  
  /* Computing MIN */
  	    r__1 = 1.f, r__2 = 1.f / dmax(xbnd,smlnum);
  	    grow = dmin(r__1,r__2);
  	    i__2 = jlast;
  	    i__1 = jinc;
  	    for (j = jfirst; i__1 < 0 ? j >= i__2 : j <= i__2; j += i__1) {
  
  /*              Exit the loop if the growth factor is too small. */
  
  		if (grow <= smlnum) {
  		    goto L80;
  		}
  
  /*              G(j) = ( 1 + CNORM(j) )*G(j-1) */
  
  		xj = cnorm[j] + 1.f;
  		grow /= xj;
  /* L70: */
  	    }
  	}
  L80:
  	;
      }
  
      if (grow * tscal > smlnum) {
  
  /*        Use the Level 2 BLAS solve if the reciprocal of the bound on */
  /*        elements of X is not too small. */
  
  	strsv_(uplo, trans, diag, n, &a[a_offset], lda, &x[1], &c__1);
      } else {
  
  /*        Use a Level 1 BLAS solve, scaling intermediate results. */
  
  	if (xmax > bignum) {
  
  /*           Scale X so that its components are less than or equal to */
  /*           BIGNUM in absolute value. */
  
  	    *scale = bignum / xmax;
  	    sscal_(n, scale, &x[1], &c__1);
  	    xmax = bignum;
  	}
  
  	if (notran) {
  
  /*           Solve A * x = b */
  
  	    i__1 = jlast;
  	    i__2 = jinc;
  	    for (j = jfirst; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) {
  
  /*              Compute x(j) = b(j) / A(j,j), scaling x if necessary. */
  
  		xj = (r__1 = x[j], dabs(r__1));
  		if (nounit) {
  		    tjjs = a[j + j * a_dim1] * tscal;
  		} else {
  		    tjjs = tscal;
  		    if (tscal == 1.f) {
  			goto L95;
  		    }
  		}
  		tjj = dabs(tjjs);
  		if (tjj > smlnum) {
  
  /*                    abs(A(j,j)) > SMLNUM: */
  
  		    if (tjj < 1.f) {
  			if (xj > tjj * bignum) {
  
  /*                          Scale x by 1/b(j). */
  
  			    rec = 1.f / xj;
  			    sscal_(n, &rec, &x[1], &c__1);
  			    *scale *= rec;
  			    xmax *= rec;
  			}
  		    }
  		    x[j] /= tjjs;
  		    xj = (r__1 = x[j], dabs(r__1));
  		} else if (tjj > 0.f) {
  
  /*                    0 < abs(A(j,j)) <= SMLNUM: */
  
  		    if (xj > tjj * bignum) {
  
  /*                       Scale x by (1/abs(x(j)))*abs(A(j,j))*BIGNUM */
  /*                       to avoid overflow when dividing by A(j,j). */
  
  			rec = tjj * bignum / xj;
  			if (cnorm[j] > 1.f) {
  
  /*                          Scale by 1/CNORM(j) to avoid overflow when */
  /*                          multiplying x(j) times column j. */
  
  			    rec /= cnorm[j];
  			}
  			sscal_(n, &rec, &x[1], &c__1);
  			*scale *= rec;
  			xmax *= rec;
  		    }
  		    x[j] /= tjjs;
  		    xj = (r__1 = x[j], dabs(r__1));
  		} else {
  
  /*                    A(j,j) = 0:  Set x(1:n) = 0, x(j) = 1, and */
  /*                    scale = 0, and compute a solution to A*x = 0. */
  
  		    i__3 = *n;
  		    for (i__ = 1; i__ <= i__3; ++i__) {
  			x[i__] = 0.f;
  /* L90: */
  		    }
  		    x[j] = 1.f;
  		    xj = 1.f;
  		    *scale = 0.f;
  		    xmax = 0.f;
  		}
  L95:
  
  /*              Scale x if necessary to avoid overflow when adding a */
  /*              multiple of column j of A. */
  
  		if (xj > 1.f) {
  		    rec = 1.f / xj;
  		    if (cnorm[j] > (bignum - xmax) * rec) {
  
  /*                    Scale x by 1/(2*abs(x(j))). */
  
  			rec *= .5f;
  			sscal_(n, &rec, &x[1], &c__1);
  			*scale *= rec;
  		    }
  		} else if (xj * cnorm[j] > bignum - xmax) {
  
  /*                 Scale x by 1/2. */
  
  		    sscal_(n, &c_b36, &x[1], &c__1);
  		    *scale *= .5f;
  		}
  
  		if (upper) {
  		    if (j > 1) {
  
  /*                    Compute the update */
  /*                       x(1:j-1) := x(1:j-1) - x(j) * A(1:j-1,j) */
  
  			i__3 = j - 1;
  			r__1 = -x[j] * tscal;
  			saxpy_(&i__3, &r__1, &a[j * a_dim1 + 1], &c__1, &x[1], 
  				 &c__1);
  			i__3 = j - 1;
  			i__ = isamax_(&i__3, &x[1], &c__1);
  			xmax = (r__1 = x[i__], dabs(r__1));
  		    }
  		} else {
  		    if (j < *n) {
  
  /*                    Compute the update */
  /*                       x(j+1:n) := x(j+1:n) - x(j) * A(j+1:n,j) */
  
  			i__3 = *n - j;
  			r__1 = -x[j] * tscal;
  			saxpy_(&i__3, &r__1, &a[j + 1 + j * a_dim1], &c__1, &
  				x[j + 1], &c__1);
  			i__3 = *n - j;
  			i__ = j + isamax_(&i__3, &x[j + 1], &c__1);
  			xmax = (r__1 = x[i__], dabs(r__1));
  		    }
  		}
  /* L100: */
  	    }
  
  	} else {
  
  /*           Solve A' * x = b */
  
  	    i__2 = jlast;
  	    i__1 = jinc;
  	    for (j = jfirst; i__1 < 0 ? j >= i__2 : j <= i__2; j += i__1) {
  
  /*              Compute x(j) = b(j) - sum A(k,j)*x(k). */
  /*                                    k<>j */
  
  		xj = (r__1 = x[j], dabs(r__1));
  		uscal = tscal;
  		rec = 1.f / dmax(xmax,1.f);
  		if (cnorm[j] > (bignum - xj) * rec) {
  
  /*                 If x(j) could overflow, scale x by 1/(2*XMAX). */
  
  		    rec *= .5f;
  		    if (nounit) {
  			tjjs = a[j + j * a_dim1] * tscal;
  		    } else {
  			tjjs = tscal;
  		    }
  		    tjj = dabs(tjjs);
  		    if (tjj > 1.f) {
  
  /*                       Divide by A(j,j) when scaling x if A(j,j) > 1. */
  
  /* Computing MIN */
  			r__1 = 1.f, r__2 = rec * tjj;
  			rec = dmin(r__1,r__2);
  			uscal /= tjjs;
  		    }
  		    if (rec < 1.f) {
  			sscal_(n, &rec, &x[1], &c__1);
  			*scale *= rec;
  			xmax *= rec;
  		    }
  		}
  
  		sumj = 0.f;
  		if (uscal == 1.f) {
  
  /*                 If the scaling needed for A in the dot product is 1, */
  /*                 call SDOT to perform the dot product. */
  
  		    if (upper) {
  			i__3 = j - 1;
  			sumj = sdot_(&i__3, &a[j * a_dim1 + 1], &c__1, &x[1], 
  				&c__1);
  		    } else if (j < *n) {
  			i__3 = *n - j;
  			sumj = sdot_(&i__3, &a[j + 1 + j * a_dim1], &c__1, &x[
  				j + 1], &c__1);
  		    }
  		} else {
  
  /*                 Otherwise, use in-line code for the dot product. */
  
  		    if (upper) {
  			i__3 = j - 1;
  			for (i__ = 1; i__ <= i__3; ++i__) {
  			    sumj += a[i__ + j * a_dim1] * uscal * x[i__];
  /* L110: */
  			}
  		    } else if (j < *n) {
  			i__3 = *n;
  			for (i__ = j + 1; i__ <= i__3; ++i__) {
  			    sumj += a[i__ + j * a_dim1] * uscal * x[i__];
  /* L120: */
  			}
  		    }
  		}
  
  		if (uscal == tscal) {
  
  /*                 Compute x(j) := ( x(j) - sumj ) / A(j,j) if 1/A(j,j) */
  /*                 was not used to scale the dotproduct. */
  
  		    x[j] -= sumj;
  		    xj = (r__1 = x[j], dabs(r__1));
  		    if (nounit) {
  			tjjs = a[j + j * a_dim1] * tscal;
  		    } else {
  			tjjs = tscal;
  			if (tscal == 1.f) {
  			    goto L135;
  			}
  		    }
  
  /*                    Compute x(j) = x(j) / A(j,j), scaling if necessary. */
  
  		    tjj = dabs(tjjs);
  		    if (tjj > smlnum) {
  
  /*                       abs(A(j,j)) > SMLNUM: */
  
  			if (tjj < 1.f) {
  			    if (xj > tjj * bignum) {
  
  /*                             Scale X by 1/abs(x(j)). */
  
  				rec = 1.f / xj;
  				sscal_(n, &rec, &x[1], &c__1);
  				*scale *= rec;
  				xmax *= rec;
  			    }
  			}
  			x[j] /= tjjs;
  		    } else if (tjj > 0.f) {
  
  /*                       0 < abs(A(j,j)) <= SMLNUM: */
  
  			if (xj > tjj * bignum) {
  
  /*                          Scale x by (1/abs(x(j)))*abs(A(j,j))*BIGNUM. */
  
  			    rec = tjj * bignum / xj;
  			    sscal_(n, &rec, &x[1], &c__1);
  			    *scale *= rec;
  			    xmax *= rec;
  			}
  			x[j] /= tjjs;
  		    } else {
  
  /*                       A(j,j) = 0:  Set x(1:n) = 0, x(j) = 1, and */
  /*                       scale = 0, and compute a solution to A'*x = 0. */
  
  			i__3 = *n;
  			for (i__ = 1; i__ <= i__3; ++i__) {
  			    x[i__] = 0.f;
  /* L130: */
  			}
  			x[j] = 1.f;
  			*scale = 0.f;
  			xmax = 0.f;
  		    }
  L135:
  		    ;
  		} else {
  
  /*                 Compute x(j) := x(j) / A(j,j)  - sumj if the dot */
  /*                 product has already been divided by 1/A(j,j). */
  
  		    x[j] = x[j] / tjjs - sumj;
  		}
  /* Computing MAX */
  		r__2 = xmax, r__3 = (r__1 = x[j], dabs(r__1));
  		xmax = dmax(r__2,r__3);
  /* L140: */
  	    }
  	}
  	*scale /= tscal;
      }
  
  /*     Scale the column norms by 1/TSCAL for return. */
  
      if (tscal != 1.f) {
  	r__1 = 1.f / tscal;
  	sscal_(n, &r__1, &cnorm[1], &c__1);
      }
  
      return 0;
  
  /*     End of SLATRS */
  
  } /* slatrs_ */
  