text: /* cpotrf.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;
  static real c_b14 = -1.f;
  static real c_b15 = 1.f;
  
  /* Subroutine */ int cpotrf_(char *uplo, integer *n, complex *a, integer *lda, 
  	 integer *info)
  {
      /* System generated locals */
      integer a_dim1, a_offset, i__1, i__2, i__3, i__4;
      complex q__1;
  
      /* Local variables */
      integer j, jb, nb;
      extern /* Subroutine */ int cgemm_(char *, char *, integer *, integer *, 
  	    integer *, complex *, complex *, integer *, complex *, integer *, 
  	    complex *, complex *, integer *), cherk_(char *, 
  	    char *, integer *, integer *, real *, complex *, integer *, real *
  , complex *, integer *);
      extern logical lsame_(char *, char *);
      extern /* Subroutine */ int ctrsm_(char *, char *, char *, char *, 
  	    integer *, integer *, complex *, complex *, integer *, complex *, 
  	    integer *);
      logical upper;
      extern /* Subroutine */ int cpotf2_(char *, integer *, complex *, integer 
  	    *, integer *), xerbla_(char *, integer *);
      extern integer ilaenv_(integer *, char *, char *, integer *, integer *, 
  	    integer *, integer *);
  
  
  /*  -- LAPACK routine (version 3.2) -- */
  /*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
  /*     November 2006 */
  
  /*     .. Scalar Arguments .. */
  /*     .. */
  /*     .. Array Arguments .. */
  /*     .. */
  
  /*  Purpose */
  /*  ======= */
  
  /*  CPOTRF computes the Cholesky factorization of a complex Hermitian */
  /*  positive definite matrix A. */
  
  /*  The factorization has the form */
  /*     A = U**H * U,  if UPLO = 'U', or */
  /*     A = L  * L**H,  if UPLO = 'L', */
  /*  where U is an upper triangular matrix and L is lower triangular. */
  
  /*  This is the block version of the algorithm, calling Level 3 BLAS. */
  
  /*  Arguments */
  /*  ========= */
  
  /*  UPLO    (input) CHARACTER*1 */
  /*          = 'U':  Upper triangle of A is stored; */
  /*          = 'L':  Lower triangle of A is stored. */
  
  /*  N       (input) INTEGER */
  /*          The order of the matrix A.  N >= 0. */
  
  /*  A       (input/output) COMPLEX array, dimension (LDA,N) */
  /*          On entry, the Hermitian 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, if INFO = 0, the factor U or L from the Cholesky */
  /*          factorization A = U**H*U or A = L*L**H. */
  
  /*  LDA     (input) INTEGER */
  /*          The leading dimension of the array A.  LDA >= max(1,N). */
  
  /*  INFO    (output) INTEGER */
  /*          = 0:  successful exit */
  /*          < 0:  if INFO = -i, the i-th argument had an illegal value */
  /*          > 0:  if INFO = i, the leading minor of order i is not */
  /*                positive definite, and the factorization could not be */
  /*                completed. */
  
  /*  ===================================================================== */
  
  /*     .. Parameters .. */
  /*     .. */
  /*     .. Local Scalars .. */
  /*     .. */
  /*     .. External Functions .. */
  /*     .. */
  /*     .. External Subroutines .. */
  /*     .. */
  /*     .. Intrinsic Functions .. */
  /*     .. */
  /*     .. Executable Statements .. */
  
  /*     Test the input parameters. */
  
      /* Parameter adjustments */
      a_dim1 = *lda;
      a_offset = 1 + a_dim1;
      a -= a_offset;
  
      /* 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_("CPOTRF", &i__1);
  	return 0;
      }
  
  /*     Quick return if possible */
  
      if (*n == 0) {
  	return 0;
      }
  
  /*     Determine the block size for this environment. */
  
      nb = ilaenv_(&c__1, "CPOTRF", uplo, n, &c_n1, &c_n1, &c_n1);
      if (nb <= 1 || nb >= *n) {
  
  /*        Use unblocked code. */
  
  	cpotf2_(uplo, n, &a[a_offset], lda, info);
      } else {
  
  /*        Use blocked code. */
  
  	if (upper) {
  
  /*           Compute the Cholesky factorization A = U'*U. */
  
  	    i__1 = *n;
  	    i__2 = nb;
  	    for (j = 1; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) {
  
  /*              Update and factorize the current diagonal block and test */
  /*              for non-positive-definiteness. */
  
  /* Computing MIN */
  		i__3 = nb, i__4 = *n - j + 1;
  		jb = min(i__3,i__4);
  		i__3 = j - 1;
  		cherk_("Upper", "Conjugate transpose", &jb, &i__3, &c_b14, &a[
  			j * a_dim1 + 1], lda, &c_b15, &a[j + j * a_dim1], lda);
  		cpotf2_("Upper", &jb, &a[j + j * a_dim1], lda, info);
  		if (*info != 0) {
  		    goto L30;
  		}
  		if (j + jb <= *n) {
  
  /*                 Compute the current block row. */
  
  		    i__3 = *n - j - jb + 1;
  		    i__4 = j - 1;
  		    q__1.r = -1.f, q__1.i = -0.f;
  		    cgemm_("Conjugate transpose", "No transpose", &jb, &i__3, 
  			    &i__4, &q__1, &a[j * a_dim1 + 1], lda, &a[(j + jb)
  			     * a_dim1 + 1], lda, &c_b1, &a[j + (j + jb) * 
  			    a_dim1], lda);
  		    i__3 = *n - j - jb + 1;
  		    ctrsm_("Left", "Upper", "Conjugate transpose", "Non-unit", 
  			     &jb, &i__3, &c_b1, &a[j + j * a_dim1], lda, &a[j 
  			    + (j + jb) * a_dim1], lda);
  		}
  /* L10: */
  	    }
  
  	} else {
  
  /*           Compute the Cholesky factorization A = L*L'. */
  
  	    i__2 = *n;
  	    i__1 = nb;
  	    for (j = 1; i__1 < 0 ? j >= i__2 : j <= i__2; j += i__1) {
  
  /*              Update and factorize the current diagonal block and test */
  /*              for non-positive-definiteness. */
  
  /* Computing MIN */
  		i__3 = nb, i__4 = *n - j + 1;
  		jb = min(i__3,i__4);
  		i__3 = j - 1;
  		cherk_("Lower", "No transpose", &jb, &i__3, &c_b14, &a[j + 
  			a_dim1], lda, &c_b15, &a[j + j * a_dim1], lda);
  		cpotf2_("Lower", &jb, &a[j + j * a_dim1], lda, info);
  		if (*info != 0) {
  		    goto L30;
  		}
  		if (j + jb <= *n) {
  
  /*                 Compute the current block column. */
  
  		    i__3 = *n - j - jb + 1;
  		    i__4 = j - 1;
  		    q__1.r = -1.f, q__1.i = -0.f;
  		    cgemm_("No transpose", "Conjugate transpose", &i__3, &jb, 
  			    &i__4, &q__1, &a[j + jb + a_dim1], lda, &a[j + 
  			    a_dim1], lda, &c_b1, &a[j + jb + j * a_dim1], lda);
  		    i__3 = *n - j - jb + 1;
  		    ctrsm_("Right", "Lower", "Conjugate transpose", "Non-unit"
  , &i__3, &jb, &c_b1, &a[j + j * a_dim1], lda, &a[
  			    j + jb + j * a_dim1], lda);
  		}
  /* L20: */
  	    }
  	}
      }
      goto L40;
  
  L30:
      *info = *info + j - 1;
  
  L40:
      return 0;
  
  /*     End of CPOTRF */
  
  } /* cpotrf_ */
  