1*> \brief \b ILAZLR scans a matrix for its last non-zero row.
2*
3*  =========== DOCUMENTATION ===========
4*
5* Online html documentation available at
6*            http://www.netlib.org/lapack/explore-html/
7*
8*> \htmlonly
9*> Download ILAZLR + dependencies
10*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/ilazlr.f">
11*> [TGZ]</a>
12*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/ilazlr.f">
13*> [ZIP]</a>
14*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/ilazlr.f">
15*> [TXT]</a>
16*> \endhtmlonly
17*
18*  Definition:
19*  ===========
20*
21*       INTEGER FUNCTION ILAZLR( M, N, A, LDA )
22*
23*       .. Scalar Arguments ..
24*       INTEGER            M, N, LDA
25*       ..
26*       .. Array Arguments ..
27*       COMPLEX*16         A( LDA, * )
28*       ..
29*
30*
31*> \par Purpose:
32*  =============
33*>
34*> \verbatim
35*>
36*> ILAZLR scans A for its last non-zero row.
37*> \endverbatim
38*
39*  Arguments:
40*  ==========
41*
42*> \param[in] M
43*> \verbatim
44*>          M is INTEGER
45*>          The number of rows of the matrix A.
46*> \endverbatim
47*>
48*> \param[in] N
49*> \verbatim
50*>          N is INTEGER
51*>          The number of columns of the matrix A.
52*> \endverbatim
53*>
54*> \param[in] A
55*> \verbatim
56*>          A is COMPLEX*16 array, dimension (LDA,N)
57*>          The m by n matrix A.
58*> \endverbatim
59*>
60*> \param[in] LDA
61*> \verbatim
62*>          LDA is INTEGER
63*>          The leading dimension of the array A. LDA >= max(1,M).
64*> \endverbatim
65*
66*  Authors:
67*  ========
68*
69*> \author Univ. of Tennessee
70*> \author Univ. of California Berkeley
71*> \author Univ. of Colorado Denver
72*> \author NAG Ltd.
73*
74*> \ingroup complex16OTHERauxiliary
75*
76*  =====================================================================
77      INTEGER FUNCTION ILAZLR( M, N, A, LDA )
78*
79*  -- LAPACK auxiliary routine --
80*  -- LAPACK is a software package provided by Univ. of Tennessee,    --
81*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
82*
83*     .. Scalar Arguments ..
84      INTEGER            M, N, LDA
85*     ..
86*     .. Array Arguments ..
87      COMPLEX*16         A( LDA, * )
88*     ..
89*
90*  =====================================================================
91*
92*     .. Parameters ..
93      COMPLEX*16       ZERO
94      PARAMETER ( ZERO = (0.0D+0, 0.0D+0) )
95*     ..
96*     .. Local Scalars ..
97      INTEGER I, J
98*     ..
99*     .. Executable Statements ..
100*
101*     Quick test for the common case where one corner is non-zero.
102      IF( M.EQ.0 ) THEN
103         ILAZLR = M
104      ELSE IF( A(M, 1).NE.ZERO .OR. A(M, N).NE.ZERO ) THEN
105         ILAZLR = M
106      ELSE
107*     Scan up each column tracking the last zero row seen.
108         ILAZLR = 0
109         DO J = 1, N
110            I=M
111            DO WHILE((A(MAX(I,1),J).EQ.ZERO).AND.(I.GE.1))
112               I=I-1
113            ENDDO
114            ILAZLR = MAX( ILAZLR, I )
115         END DO
116      END IF
117      RETURN
118      END
119