Chris@202: /* dgetrf.f -- translated by f2c (version 20061008).
Chris@202:    You must link the resulting object file with libf2c:
Chris@202: 	on Microsoft Windows system, link with libf2c.lib;
Chris@202: 	on Linux or Unix systems, link with .../path/to/libf2c.a -lm
Chris@202: 	or, if you install libf2c.a in a standard place, with -lf2c -lm
Chris@202: 	-- in that order, at the end of the command line, as in
Chris@202: 		cc *.o -lf2c -lm
Chris@202: 	Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
Chris@202: 
Chris@202: 		http://www.netlib.org/f2c/libf2c.zip
Chris@202: */
Chris@202: 
Chris@202: #include "f2c.h"
Chris@202: #include "blaswrap.h"
Chris@202: 
Chris@202: /* Table of constant values */
Chris@202: 
Chris@202: static integer c__1 = 1;
Chris@202: static integer c_n1 = -1;
Chris@202: static doublereal c_b16 = 1.;
Chris@202: static doublereal c_b19 = -1.;
Chris@202: 
Chris@202: /* Subroutine */ int dgetrf_(integer *m, integer *n, doublereal *a, integer *
Chris@202: 	lda, integer *ipiv, integer *info)
Chris@202: {
Chris@202:     /* System generated locals */
Chris@202:     integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5;
Chris@202: 
Chris@202:     /* Local variables */
Chris@202:     integer i__, j, jb, nb;
Chris@202:     extern /* Subroutine */ int dgemm_(char *, char *, integer *, integer *, 
Chris@202: 	    integer *, doublereal *, doublereal *, integer *, doublereal *, 
Chris@202: 	    integer *, doublereal *, doublereal *, integer *);
Chris@202:     integer iinfo;
Chris@202:     extern /* Subroutine */ int dtrsm_(char *, char *, char *, char *, 
Chris@202: 	    integer *, integer *, doublereal *, doublereal *, integer *, 
Chris@202: 	    doublereal *, integer *), dgetf2_(
Chris@202: 	    integer *, integer *, doublereal *, integer *, integer *, integer 
Chris@202: 	    *), xerbla_(char *, integer *);
Chris@202:     extern integer ilaenv_(integer *, char *, char *, integer *, integer *, 
Chris@202: 	    integer *, integer *);
Chris@202:     extern /* Subroutine */ int dlaswp_(integer *, doublereal *, integer *, 
Chris@202: 	    integer *, integer *, integer *, integer *);
Chris@202: 
Chris@202: 
Chris@202: /*  -- LAPACK routine (version 3.2) -- */
Chris@202: /*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
Chris@202: /*     November 2006 */
Chris@202: 
Chris@202: /*     .. Scalar Arguments .. */
Chris@202: /*     .. */
Chris@202: /*     .. Array Arguments .. */
Chris@202: /*     .. */
Chris@202: 
Chris@202: /*  Purpose */
Chris@202: /*  ======= */
Chris@202: 
Chris@202: /*  DGETRF computes an LU factorization of a general M-by-N matrix A */
Chris@202: /*  using partial pivoting with row interchanges. */
Chris@202: 
Chris@202: /*  The factorization has the form */
Chris@202: /*     A = P * L * U */
Chris@202: /*  where P is a permutation matrix, L is lower triangular with unit */
Chris@202: /*  diagonal elements (lower trapezoidal if m > n), and U is upper */
Chris@202: /*  triangular (upper trapezoidal if m < n). */
Chris@202: 
Chris@202: /*  This is the right-looking Level 3 BLAS version of the algorithm. */
Chris@202: 
Chris@202: /*  Arguments */
Chris@202: /*  ========= */
Chris@202: 
Chris@202: /*  M       (input) INTEGER */
Chris@202: /*          The number of rows of the matrix A.  M >= 0. */
Chris@202: 
Chris@202: /*  N       (input) INTEGER */
Chris@202: /*          The number of columns of the matrix A.  N >= 0. */
Chris@202: 
Chris@202: /*  A       (input/output) DOUBLE PRECISION array, dimension (LDA,N) */
Chris@202: /*          On entry, the M-by-N matrix to be factored. */
Chris@202: /*          On exit, the factors L and U from the factorization */
Chris@202: /*          A = P*L*U; the unit diagonal elements of L are not stored. */
Chris@202: 
Chris@202: /*  LDA     (input) INTEGER */
Chris@202: /*          The leading dimension of the array A.  LDA >= max(1,M). */
Chris@202: 
Chris@202: /*  IPIV    (output) INTEGER array, dimension (min(M,N)) */
Chris@202: /*          The pivot indices; for 1 <= i <= min(M,N), row i of the */
Chris@202: /*          matrix was interchanged with row IPIV(i). */
Chris@202: 
Chris@202: /*  INFO    (output) INTEGER */
Chris@202: /*          = 0:  successful exit */
Chris@202: /*          < 0:  if INFO = -i, the i-th argument had an illegal value */
Chris@202: /*          > 0:  if INFO = i, U(i,i) is exactly zero. The factorization */
Chris@202: /*                has been completed, but the factor U is exactly */
Chris@202: /*                singular, and division by zero will occur if it is used */
Chris@202: /*                to solve a system of equations. */
Chris@202: 
Chris@202: /*  ===================================================================== */
Chris@202: 
Chris@202: /*     .. Parameters .. */
Chris@202: /*     .. */
Chris@202: /*     .. Local Scalars .. */
Chris@202: /*     .. */
Chris@202: /*     .. External Subroutines .. */
Chris@202: /*     .. */
Chris@202: /*     .. External Functions .. */
Chris@202: /*     .. */
Chris@202: /*     .. Intrinsic Functions .. */
Chris@202: /*     .. */
Chris@202: /*     .. Executable Statements .. */
Chris@202: 
Chris@202: /*     Test the input parameters. */
Chris@202: 
Chris@202:     /* Parameter adjustments */
Chris@202:     a_dim1 = *lda;
Chris@202:     a_offset = 1 + a_dim1;
Chris@202:     a -= a_offset;
Chris@202:     --ipiv;
Chris@202: 
Chris@202:     /* Function Body */
Chris@202:     *info = 0;
Chris@202:     if (*m < 0) {
Chris@202: 	*info = -1;
Chris@202:     } else if (*n < 0) {
Chris@202: 	*info = -2;
Chris@202:     } else if (*lda < max(1,*m)) {
Chris@202: 	*info = -4;
Chris@202:     }
Chris@202:     if (*info != 0) {
Chris@202: 	i__1 = -(*info);
Chris@202: 	xerbla_("DGETRF", &i__1);
Chris@202: 	return 0;
Chris@202:     }
Chris@202: 
Chris@202: /*     Quick return if possible */
Chris@202: 
Chris@202:     if (*m == 0 || *n == 0) {
Chris@202: 	return 0;
Chris@202:     }
Chris@202: 
Chris@202: /*     Determine the block size for this environment. */
Chris@202: 
Chris@202:     nb = ilaenv_(&c__1, "DGETRF", " ", m, n, &c_n1, &c_n1);
Chris@202:     if (nb <= 1 || nb >= min(*m,*n)) {
Chris@202: 
Chris@202: /*        Use unblocked code. */
Chris@202: 
Chris@202: 	dgetf2_(m, n, &a[a_offset], lda, &ipiv[1], info);
Chris@202:     } else {
Chris@202: 
Chris@202: /*        Use blocked code. */
Chris@202: 
Chris@202: 	i__1 = min(*m,*n);
Chris@202: 	i__2 = nb;
Chris@202: 	for (j = 1; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) {
Chris@202: /* Computing MIN */
Chris@202: 	    i__3 = min(*m,*n) - j + 1;
Chris@202: 	    jb = min(i__3,nb);
Chris@202: 
Chris@202: /*           Factor diagonal and subdiagonal blocks and test for exact */
Chris@202: /*           singularity. */
Chris@202: 
Chris@202: 	    i__3 = *m - j + 1;
Chris@202: 	    dgetf2_(&i__3, &jb, &a[j + j * a_dim1], lda, &ipiv[j], &iinfo);
Chris@202: 
Chris@202: /*           Adjust INFO and the pivot indices. */
Chris@202: 
Chris@202: 	    if (*info == 0 && iinfo > 0) {
Chris@202: 		*info = iinfo + j - 1;
Chris@202: 	    }
Chris@202: /* Computing MIN */
Chris@202: 	    i__4 = *m, i__5 = j + jb - 1;
Chris@202: 	    i__3 = min(i__4,i__5);
Chris@202: 	    for (i__ = j; i__ <= i__3; ++i__) {
Chris@202: 		ipiv[i__] = j - 1 + ipiv[i__];
Chris@202: /* L10: */
Chris@202: 	    }
Chris@202: 
Chris@202: /*           Apply interchanges to columns 1:J-1. */
Chris@202: 
Chris@202: 	    i__3 = j - 1;
Chris@202: 	    i__4 = j + jb - 1;
Chris@202: 	    dlaswp_(&i__3, &a[a_offset], lda, &j, &i__4, &ipiv[1], &c__1);
Chris@202: 
Chris@202: 	    if (j + jb <= *n) {
Chris@202: 
Chris@202: /*              Apply interchanges to columns J+JB:N. */
Chris@202: 
Chris@202: 		i__3 = *n - j - jb + 1;
Chris@202: 		i__4 = j + jb - 1;
Chris@202: 		dlaswp_(&i__3, &a[(j + jb) * a_dim1 + 1], lda, &j, &i__4, &
Chris@202: 			ipiv[1], &c__1);
Chris@202: 
Chris@202: /*              Compute block row of U. */
Chris@202: 
Chris@202: 		i__3 = *n - j - jb + 1;
Chris@202: 		dtrsm_("Left", "Lower", "No transpose", "Unit", &jb, &i__3, &
Chris@202: 			c_b16, &a[j + j * a_dim1], lda, &a[j + (j + jb) * 
Chris@202: 			a_dim1], lda);
Chris@202: 		if (j + jb <= *m) {
Chris@202: 
Chris@202: /*                 Update trailing submatrix. */
Chris@202: 
Chris@202: 		    i__3 = *m - j - jb + 1;
Chris@202: 		    i__4 = *n - j - jb + 1;
Chris@202: 		    dgemm_("No transpose", "No transpose", &i__3, &i__4, &jb, 
Chris@202: 			    &c_b19, &a[j + jb + j * a_dim1], lda, &a[j + (j + 
Chris@202: 			    jb) * a_dim1], lda, &c_b16, &a[j + jb + (j + jb) *
Chris@202: 			     a_dim1], lda);
Chris@202: 		}
Chris@202: 	    }
Chris@202: /* L20: */
Chris@202: 	}
Chris@202:     }
Chris@202:     return 0;
Chris@202: 
Chris@202: /*     End of DGETRF */
Chris@202: 
Chris@202: } /* dgetrf_ */