--- /dev/null
+#include "clapack.h"
+
+/* Table of constant values */
+
+static integer c__1 = 1;
+static integer c_n1 = -1;
+static real c_b16 = 1.f;
+static real c_b19 = -1.f;
+
+/* Subroutine */ int sgetrf_(integer *m, integer *n, real *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;
+
+ /* Local variables */
+ integer i__, j, jb, nb, iinfo;
+ extern /* Subroutine */ int sgemm_(char *, char *, integer *, integer *,
+ integer *, real *, real *, integer *, real *, integer *, real *,
+ real *, integer *), strsm_(char *, char *, char *,
+ char *, integer *, integer *, real *, real *, integer *, real *,
+ integer *), sgetf2_(integer *,
+ integer *, real *, integer *, integer *, integer *), xerbla_(char
+ *, integer *);
+ extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
+ integer *, integer *);
+ extern /* Subroutine */ int slaswp_(integer *, real *, integer *, integer
+ *, integer *, integer *, integer *);
+
+
+/* -- LAPACK routine (version 3.1) -- */
+/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
+/* November 2006 */
+
+/* .. Scalar Arguments .. */
+/* .. */
+/* .. Array Arguments .. */
+/* .. */
+
+/* Purpose */
+/* ======= */
+
+/* SGETRF 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 right-looking 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) REAL 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_("SGETRF", &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, "SGETRF", " ", m, n, &c_n1, &c_n1);
+ if (nb <= 1 || nb >= min(*m,*n)) {
+
+/* Use unblocked code. */
+
+ sgetf2_(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);
+
+/* Factor diagonal and subdiagonal blocks and test for exact */
+/* singularity. */
+
+ i__3 = *m - j + 1;
+ sgetf2_(&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 columns 1:J-1. */
+
+ i__3 = j - 1;
+ i__4 = j + jb - 1;
+ slaswp_(&i__3, &a[a_offset], lda, &j, &i__4, &ipiv[1], &c__1);
+
+ if (j + jb <= *n) {
+
+/* Apply interchanges to columns J+JB:N. */
+
+ i__3 = *n - j - jb + 1;
+ i__4 = j + jb - 1;
+ slaswp_(&i__3, &a[(j + jb) * a_dim1 + 1], lda, &j, &i__4, &
+ ipiv[1], &c__1);
+
+/* Compute block row of U. */
+
+ i__3 = *n - j - jb + 1;
+ strsm_("Left", "Lower", "No transpose", "Unit", &jb, &i__3, &
+ c_b16, &a[j + j * a_dim1], lda, &a[j + (j + jb) *
+ a_dim1], lda);
+ if (j + jb <= *m) {
+
+/* Update trailing submatrix. */
+
+ i__3 = *m - j - jb + 1;
+ i__4 = *n - j - jb + 1;
+ sgemm_("No transpose", "No transpose", &i__3, &i__4, &jb,
+ &c_b19, &a[j + jb + j * a_dim1], lda, &a[j + (j +
+ jb) * a_dim1], lda, &c_b16, &a[j + jb + (j + jb) *
+ a_dim1], lda);
+ }
+ }
+/* L20: */
+ }
+ }
+ return 0;
+
+/* End of SGETRF */
+
+} /* sgetrf_ */
projects / opencv / blobdiff