Update to 2.0.0 tree from current Fremantle build

[opencv] / 3rdparty / lapack / spotrs.c

diff --git a/3rdparty/lapack/spotrs.c b/3rdparty/lapack/spotrs.c
new file mode 100644 (file)
index 0000000..e71ce75
--- /dev/null
+++ b/3rdparty/lapack/spotrs.c
@@ -0,0 +1,151 @@
+#include "clapack.h"
+
+/* Table of constant values */
+
+static real c_b9 = 1.f;
+
+/* Subroutine */ int spotrs_(char *uplo, integer *n, integer *nrhs, real *a, 
+       integer *lda, real *b, integer *ldb, integer *info)
+{
+    /* System generated locals */
+    integer a_dim1, a_offset, b_dim1, b_offset, i__1;
+
+    /* Local variables */
+    extern logical lsame_(char *, char *);
+    logical upper;
+    extern /* Subroutine */ int strsm_(char *, char *, char *, char *, 
+           integer *, integer *, real *, real *, integer *, real *, integer *
+), xerbla_(char *, integer *);
+
+
+/*  -- LAPACK routine (version 3.1) -- */
+/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
+/*     November 2006 */
+
+/*     .. Scalar Arguments .. */
+/*     .. */
+/*     .. Array Arguments .. */
+/*     .. */
+
+/*  Purpose */
+/*  ======= */
+
+/*  SPOTRS solves a system of linear equations A*X = B with a symmetric */
+/*  positive definite matrix A using the Cholesky factorization */
+/*  A = U**T*U or A = L*L**T computed by SPOTRF. */
+
+/*  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. */
+
+/*  NRHS    (input) INTEGER */
+/*          The number of right hand sides, i.e., the number of columns */
+/*          of the matrix B.  NRHS >= 0. */
+
+/*  A       (input) REAL array, dimension (LDA,N) */
+/*          The triangular factor U or L from the Cholesky factorization */
+/*          A = U**T*U or A = L*L**T, as computed by SPOTRF. */
+
+/*  LDA     (input) INTEGER */
+/*          The leading dimension of the array A.  LDA >= max(1,N). */
+
+/*  B       (input/output) REAL array, dimension (LDB,NRHS) */
+/*          On entry, the right hand side matrix B. */
+/*          On exit, the solution matrix X. */
+
+/*  LDB     (input) INTEGER */
+/*          The leading dimension of the array B.  LDB >= max(1,N). */
+
+/*  INFO    (output) INTEGER */
+/*          = 0:  successful exit */
+/*          < 0:  if INFO = -i, the i-th argument had an illegal value */
+
+/*  ===================================================================== */
+
+/*     .. 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;
+    b_dim1 = *ldb;
+    b_offset = 1 + b_dim1;
+    b -= b_offset;
+
+    /* Function Body */
+    *info = 0;
+    upper = lsame_(uplo, "U");
+    if (! upper && ! lsame_(uplo, "L")) {
+       *info = -1;
+    } else if (*n < 0) {
+       *info = -2;
+    } else if (*nrhs < 0) {
+       *info = -3;
+    } else if (*lda < max(1,*n)) {
+       *info = -5;
+    } else if (*ldb < max(1,*n)) {
+       *info = -7;
+    }
+    if (*info != 0) {
+       i__1 = -(*info);
+       xerbla_("SPOTRS", &i__1);
+       return 0;
+    }
+
+/*     Quick return if possible */
+
+    if (*n == 0 || *nrhs == 0) {
+       return 0;
+    }
+
+    if (upper) {
+
+/*        Solve A*X = B where A = U'*U. */
+
+/*        Solve U'*X = B, overwriting B with X. */
+
+       strsm_("Left", "Upper", "Transpose", "Non-unit", n, nrhs, &c_b9, &a[
+               a_offset], lda, &b[b_offset], ldb);
+
+/*        Solve U*X = B, overwriting B with X. */
+
+       strsm_("Left", "Upper", "No transpose", "Non-unit", n, nrhs, &c_b9, &
+               a[a_offset], lda, &b[b_offset], ldb);
+    } else {
+
+/*        Solve A*X = B where A = L*L'. */
+
+/*        Solve L*X = B, overwriting B with X. */
+
+       strsm_("Left", "Lower", "No transpose", "Non-unit", n, nrhs, &c_b9, &
+               a[a_offset], lda, &b[b_offset], ldb);
+
+/*        Solve L'*X = B, overwriting B with X. */
+
+       strsm_("Left", "Lower", "Transpose", "Non-unit", n, nrhs, &c_b9, &a[
+               a_offset], lda, &b[b_offset], ldb);
+    }
+
+    return 0;
+
+/*     End of SPOTRS */
+
+} /* spotrs_ */