Update to 2.0.0 tree from current Fremantle build

[opencv] / 3rdparty / lapack / strti2.c

diff --git a/3rdparty/lapack/strti2.c b/3rdparty/lapack/strti2.c
new file mode 100644 (file)
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+++ b/3rdparty/lapack/strti2.c
@@ -0,0 +1,170 @@
+#include "clapack.h"
+
+/* Table of constant values */
+
+static integer c__1 = 1;
+
+/* Subroutine */ int strti2_(char *uplo, char *diag, integer *n, real *a, 
+       integer *lda, integer *info)
+{
+    /* System generated locals */
+    integer a_dim1, a_offset, i__1, i__2;
+
+    /* Local variables */
+    integer j;
+    real ajj;
+    extern logical lsame_(char *, char *);
+    extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *);
+    logical upper;
+    extern /* Subroutine */ int strmv_(char *, char *, char *, integer *, 
+           real *, integer *, real *, integer *), 
+           xerbla_(char *, integer *);
+    logical nounit;
+
+
+/*  -- LAPACK routine (version 3.1) -- */
+/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
+/*     November 2006 */
+
+/*     .. Scalar Arguments .. */
+/*     .. */
+/*     .. Array Arguments .. */
+/*     .. */
+
+/*  Purpose */
+/*  ======= */
+
+/*  STRTI2 computes the inverse of a real upper or lower triangular */
+/*  matrix. */
+
+/*  This is the Level 2 BLAS version of the algorithm. */
+
+/*  Arguments */
+/*  ========= */
+
+/*  UPLO    (input) CHARACTER*1 */
+/*          Specifies whether the matrix A is upper or lower triangular. */
+/*          = 'U':  Upper triangular */
+/*          = 'L':  Lower triangular */
+
+/*  DIAG    (input) CHARACTER*1 */
+/*          Specifies whether or not the matrix A is unit triangular. */
+/*          = 'N':  Non-unit triangular */
+/*          = 'U':  Unit triangular */
+
+/*  N       (input) INTEGER */
+/*          The order of the matrix A.  N >= 0. */
+
+/*  A       (input/output) REAL array, dimension (LDA,N) */
+/*          On entry, the triangular matrix A.  If UPLO = 'U', the */
+/*          leading n by n upper triangular part of the array A contains */
+/*          the upper triangular matrix, and the strictly lower */
+/*          triangular part of A is not referenced.  If UPLO = 'L', the */
+/*          leading n by n lower triangular part of the array A contains */
+/*          the lower triangular matrix, and the strictly upper */
+/*          triangular part of A is not referenced.  If DIAG = 'U', the */
+/*          diagonal elements of A are also not referenced and are */
+/*          assumed to be 1. */
+
+/*          On exit, the (triangular) inverse of the original matrix, in */
+/*          the same storage format. */
+
+/*  LDA     (input) INTEGER */
+/*          The leading dimension of the array A.  LDA >= max(1,N). */
+
+/*  INFO    (output) INTEGER */
+/*          = 0: successful exit */
+/*          < 0: if INFO = -k, the k-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;
+
+    /* Function Body */
+    *info = 0;
+    upper = lsame_(uplo, "U");
+    nounit = lsame_(diag, "N");
+    if (! upper && ! lsame_(uplo, "L")) {
+       *info = -1;
+    } else if (! nounit && ! lsame_(diag, "U")) {
+       *info = -2;
+    } else if (*n < 0) {
+       *info = -3;
+    } else if (*lda < max(1,*n)) {
+       *info = -5;
+    }
+    if (*info != 0) {
+       i__1 = -(*info);
+       xerbla_("STRTI2", &i__1);
+       return 0;
+    }
+
+    if (upper) {
+
+/*        Compute inverse of upper triangular matrix. */
+
+       i__1 = *n;
+       for (j = 1; j <= i__1; ++j) {
+           if (nounit) {
+               a[j + j * a_dim1] = 1.f / a[j + j * a_dim1];
+               ajj = -a[j + j * a_dim1];
+           } else {
+               ajj = -1.f;
+           }
+
+/*           Compute elements 1:j-1 of j-th column. */
+
+           i__2 = j - 1;
+           strmv_("Upper", "No transpose", diag, &i__2, &a[a_offset], lda, &
+                   a[j * a_dim1 + 1], &c__1);
+           i__2 = j - 1;
+           sscal_(&i__2, &ajj, &a[j * a_dim1 + 1], &c__1);
+/* L10: */
+       }
+    } else {
+
+/*        Compute inverse of lower triangular matrix. */
+
+       for (j = *n; j >= 1; --j) {
+           if (nounit) {
+               a[j + j * a_dim1] = 1.f / a[j + j * a_dim1];
+               ajj = -a[j + j * a_dim1];
+           } else {
+               ajj = -1.f;
+           }
+           if (j < *n) {
+
+/*              Compute elements j+1:n of j-th column. */
+
+               i__1 = *n - j;
+               strmv_("Lower", "No transpose", diag, &i__1, &a[j + 1 + (j + 
+                       1) * a_dim1], lda, &a[j + 1 + j * a_dim1], &c__1);
+               i__1 = *n - j;
+               sscal_(&i__1, &ajj, &a[j + 1 + j * a_dim1], &c__1);
+           }
+/* L20: */
+       }
+    }
+
+    return 0;
+
+/*     End of STRTI2 */
+
+} /* strti2_ */