aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/clapack/iladlr.c
blob: f1626e479086546ee6171755e08903591a955a72 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
/* iladlr.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"

integer iladlr_(integer *m, integer *n, doublereal *a, integer *lda)
{
    /* System generated locals */
    integer a_dim1, a_offset, ret_val, i__1;

    /* Local variables */
    integer i__, j;


/*  -- LAPACK auxiliary routine (version 3.2.1)                        -- */

/*  -- April 2009                                                      -- */

/*  -- LAPACK is a software package provided by Univ. of Tennessee,    -- */
/*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  ILADLR scans A for its last non-zero row. */

/*  Arguments */
/*  ========= */

/*  M       (input) INTEGER */
/*          The number of rows of the matrix A. */

/*  N       (input) INTEGER */
/*          The number of columns of the matrix A. */

/*  A       (input) DOUBLE PRECISION array, dimension (LDA,N) */
/*          The m by n matrix A. */

/*  LDA     (input) INTEGER */
/*          The leading dimension of the array A. LDA >= max(1,M). */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. Executable Statements .. */

/*     Quick test for the common case where one corner is non-zero. */
    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;

    /* Function Body */
    if (*m == 0) {
	ret_val = *m;
    } else if (a[*m + a_dim1] != 0. || a[*m + *n * a_dim1] != 0.) {
	ret_val = *m;
    } else {
/*     Scan up each column tracking the last zero row seen. */
	ret_val = 0;
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    for (i__ = *m; i__ >= 1; --i__) {
		if (a[i__ + j * a_dim1] != 0.) {
		    break;
		}
	    }
	    ret_val = max(ret_val,i__);
	}
    }
    return ret_val;
} /* iladlr_ */