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
|
SUBROUTINE SCSHFT( M, N, OFFSET, A, LDA )
*
* -- PBLAS auxiliary routine (version 2.0) --
* University of Tennessee, Knoxville, Oak Ridge National Laboratory,
* and University of California, Berkeley.
* April 1, 1998
*
* .. Scalar Arguments ..
INTEGER LDA, M, N, OFFSET
* ..
* .. Array Arguments ..
REAL A( LDA, * )
* ..
*
* Purpose
* =======
*
* SCSHFT shifts columns of an m by n array A by OFFSET.
*
* Arguments
* =========
*
* M (local input) INTEGER
* On entry, M specifies the number of rows of A. M must be at
* least zero.
*
* N (local input) INTEGER
* On entry, N specifies the number of columns of A to be
* shifted. N must be at least zero.
*
* OFFSET (local input) INTEGER
* On entry, OFFSET specifies the offset by which the columns of
* A should be shifted. OFFSET can be positive or negative (see
* below for further details). When OFFSET is positive, the co-
* lumns are shifted to the right. When OFFSET is negative, the
* columns of A are shifted to the left.
*
* A (local input/local output) REAL array
* On entry, A is an array of dimension ( LDA, N+ABS(OFFSET) ).
* On exit, A contains the shifted array.
*
* LDA (local input) INTEGER
* On entry, LDA specifies the leading dimension of the array A.
* LDA must be at least max( 1, M ).
*
* Further Details
* ===============
*
* N=3 OFFSET=6 -OFFSET=6 N=3
* ------------------- -------------------
* | 1 2 3 4 5 6 7 8 9 | M | 1 2 3 4 5 6 7 8 9 |
* ------------------- -------------------
* V V
* ------------------- -------------------
* | 1 2 3 4 5 6 1 2 3 | M | 7 8 9 4 5 6 7 8 9 |
* ------------------- -------------------
* OFFSET >= 0 OFFSET <= 0
*
* -- Written on April 1, 1998 by
* Antoine Petitet, University of Tennessee, Knoxville 37996, USA.
*
* =====================================================================
*
* .. Local Scalars ..
INTEGER I, J
* ..
* .. Executable Statements ..
*
IF( ( OFFSET.EQ.0 ).OR.( M.LE.0 ).OR.( N.LE.0 ) )
$ RETURN
*
IF( OFFSET.GT.0 ) THEN
DO 20 J = N, 1, -1
DO 10 I = 1, M
A( I, J+OFFSET ) = A( I, J )
10 CONTINUE
20 CONTINUE
ELSE
DO 40 J = 1, N
DO 30 I = 1, M
A( I, J ) = A( I, J-OFFSET )
30 CONTINUE
40 CONTINUE
END IF
*
RETURN
*
* End of SCSHFT
*
END
|
