text: /* cgetrf.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 complex c_b1 = {1.f,0.f};
  static integer c__1 = 1;
  static integer c_n1 = -1;
  
  /* Subroutine */ int cgetrf_(integer *m, integer *n, complex *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;
      complex q__1;
  
      /* Local variables */
      integer i__, j, jb, nb;
      extern /* Subroutine */ int cgemm_(char *, char *, integer *, integer *, 
  	    integer *, complex *, complex *, integer *, complex *, integer *, 
  	    complex *, complex *, integer *);
      integer iinfo;
      extern /* Subroutine */ int ctrsm_(char *, char *, char *, char *, 
  	    integer *, integer *, complex *, complex *, integer *, complex *, 
  	    integer *), cgetf2_(integer *, 
  	    integer *, complex *, integer *, integer *, integer *), xerbla_(
  	    char *, integer *);
      extern integer ilaenv_(integer *, char *, char *, integer *, integer *, 
  	    integer *, integer *);
      extern /* Subroutine */ int claswp_(integer *, complex *, integer *, 
  	    integer *, integer *, integer *, integer *);
  
  
  /*  -- LAPACK routine (version 3.1) -- */
  /*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
  /*     March 2008 */
  
  /*     .. Scalar Arguments .. */
  /*     .. */
  /*     .. Array Arguments .. */
  /*     .. */
  
  /*  Purpose */
  /*  ======= */
  
  /*  CGETRF computes an LU factorization of a general M-by-N matrix A */
  /*  using partial pivoting with row interchanges. */
  
  /*  The factorization has the form */
  /*     A = P * L * U */
  /*  where P is a permutation matrix, L is lower triangular with unit */
  /*  diagonal elements (lower trapezoidal if m > n), and U is upper */
  /*  triangular (upper trapezoidal if m < n). */
  
  /*  This is the Crout Level 3 BLAS version of the algorithm. */
  
  /*  Arguments */
  /*  ========= */
  
  /*  M       (input) INTEGER */
  /*          The number of rows of the matrix A.  M >= 0. */
  
  /*  N       (input) INTEGER */
  /*          The number of columns of the matrix A.  N >= 0. */
  
  /*  A       (input/output) COMPLEX array, dimension (LDA,N) */
  /*          On entry, the M-by-N matrix to be factored. */
  /*          On exit, the factors L and U from the factorization */
  /*          A = P*L*U; the unit diagonal elements of L are not stored. */
  
  /*  LDA     (input) INTEGER */
  /*          The leading dimension of the array A.  LDA >= max(1,M). */
  
  /*  IPIV    (output) INTEGER array, dimension (min(M,N)) */
  /*          The pivot indices; for 1 <= i <= min(M,N), row i of the */
  /*          matrix was interchanged with row IPIV(i). */
  
  /*  INFO    (output) INTEGER */
  /*          = 0:  successful exit */
  /*          < 0:  if INFO = -i, the i-th argument had an illegal value */
  /*          > 0:  if INFO = i, U(i,i) is exactly zero. The factorization */
  /*                has been completed, but the factor U is exactly */
  /*                singular, and division by zero will occur if it is used */
  /*                to solve a system of equations. */
  
  /*  ===================================================================== */
  
  /*     .. Parameters .. */
  /*     .. */
  /*     .. Local Scalars .. */
  /*     .. */
  /*     .. External Subroutines .. */
  /*     .. */
  /*     .. External Functions .. */
  /*     .. */
  /*     .. Intrinsic Functions .. */
  /*     .. */
  /*     .. Executable Statements .. */
  
  /*     Test the input parameters. */
  
      /* Parameter adjustments */
      a_dim1 = *lda;
      a_offset = 1 + a_dim1;
      a -= a_offset;
      --ipiv;
  
      /* Function Body */
      *info = 0;
      if (*m < 0) {
  	*info = -1;
      } else if (*n < 0) {
  	*info = -2;
      } else if (*lda < max(1,*m)) {
  	*info = -4;
      }
      if (*info != 0) {
  	i__1 = -(*info);
  	xerbla_("CGETRF", &i__1);
  	return 0;
      }
  
  /*     Quick return if possible */
  
      if (*m == 0 || *n == 0) {
  	return 0;
      }
  
  /*     Determine the block size for this environment. */
  
      nb = ilaenv_(&c__1, "CGETRF", " ", m, n, &c_n1, &c_n1);
      if (nb <= 1 || nb >= min(*m,*n)) {
  
  /*        Use unblocked code. */
  
  	cgetf2_(m, n, &a[a_offset], lda, &ipiv[1], info);
      } else {
  
  /*        Use blocked code. */
  
  	i__1 = min(*m,*n);
  	i__2 = nb;
  	for (j = 1; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) {
  /* Computing MIN */
  	    i__3 = min(*m,*n) - j + 1;
  	    jb = min(i__3,nb);
  
  /*           Update current block. */
  
  	    i__3 = *m - j + 1;
  	    i__4 = j - 1;
  	    q__1.r = -1.f, q__1.i = -0.f;
  	    cgemm_("No transpose", "No transpose", &i__3, &jb, &i__4, &q__1, &
  		    a[j + a_dim1], lda, &a[j * a_dim1 + 1], lda, &c_b1, &a[j 
  		    + j * a_dim1], lda);
  
  /*           Factor diagonal and subdiagonal blocks and test for exact */
  /*           singularity. */
  
  	    i__3 = *m - j + 1;
  	    cgetf2_(&i__3, &jb, &a[j + j * a_dim1], lda, &ipiv[j], &iinfo);
  
  /*           Adjust INFO and the pivot indices. */
  
  	    if (*info == 0 && iinfo > 0) {
  		*info = iinfo + j - 1;
  	    }
  /* Computing MIN */
  	    i__4 = *m, i__5 = j + jb - 1;
  	    i__3 = min(i__4,i__5);
  	    for (i__ = j; i__ <= i__3; ++i__) {
  		ipiv[i__] = j - 1 + ipiv[i__];
  /* L10: */
  	    }
  
  /*           Apply interchanges to column 1:J-1 */
  
  	    i__3 = j - 1;
  	    i__4 = j + jb - 1;
  	    claswp_(&i__3, &a[a_offset], lda, &j, &i__4, &ipiv[1], &c__1);
  
  	    if (j + jb <= *n) {
  
  /*              Apply interchanges to column J+JB:N */
  
  		i__3 = *n - j - jb + 1;
  		i__4 = j + jb - 1;
  		claswp_(&i__3, &a[(j + jb) * a_dim1 + 1], lda, &j, &i__4, &
  			ipiv[1], &c__1);
  
  		i__3 = *n - j - jb + 1;
  		i__4 = j - 1;
  		q__1.r = -1.f, q__1.i = -0.f;
  		cgemm_("No transpose", "No transpose", &jb, &i__3, &i__4, &
  			q__1, &a[j + a_dim1], lda, &a[(j + jb) * a_dim1 + 1], 
  			lda, &c_b1, &a[j + (j + jb) * a_dim1], lda);
  
  /*              Compute block row of U. */
  
  		i__3 = *n - j - jb + 1;
  		ctrsm_("Left", "Lower", "No transpose", "Unit", &jb, &i__3, &
  			c_b1, &a[j + j * a_dim1], lda, &a[j + (j + jb) * 
  			a_dim1], lda);
  	    }
  /* L20: */
  	}
      }
      return 0;
  
  /*     End of CGETRF */
  
  } /* cgetrf_ */
  