summaryrefslogtreecommitdiff
path: root/SRC/zla_wwaddw.f
blob: b4f9df33284a02ef14e8add2d2192188c08a67c1 (plain)
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
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
*> \brief \b ZLA_WWADDW adds a vector into a doubled-single vector.
*
*  =========== DOCUMENTATION ===========
*
* Online html documentation available at
*            http://www.netlib.org/lapack/explore-html/
*
*> \htmlonly
*> Download ZLA_WWADDW + dependencies
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/zla_wwaddw.f">
*> [TGZ]</a>
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/zla_wwaddw.f">
*> [ZIP]</a>
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/zla_wwaddw.f">
*> [TXT]</a>
*> \endhtmlonly
*
*  Definition:
*  ===========
*
*       SUBROUTINE ZLA_WWADDW( N, X, Y, W )
*
*       .. Scalar Arguments ..
*       INTEGER            N
*       ..
*       .. Array Arguments ..
*       COMPLEX*16         X( * ), Y( * ), W( * )
*       ..
*
*
*> \par Purpose:
*  =============
*>
*> \verbatim
*>
*>    ZLA_WWADDW adds a vector W into a doubled-single vector (X, Y).
*>
*>    This works for all extant IBM's hex and binary floating point
*>    arithmetics, but not for decimal.
*> \endverbatim
*
*  Arguments:
*  ==========
*
*> \param[in] N
*> \verbatim
*>          N is INTEGER
*>            The length of vectors X, Y, and W.
*> \endverbatim
*>
*> \param[in,out] X
*> \verbatim
*>          X is COMPLEX*16 array, dimension (N)
*>            The first part of the doubled-single accumulation vector.
*> \endverbatim
*>
*> \param[in,out] Y
*> \verbatim
*>          Y is COMPLEX*16 array, dimension (N)
*>            The second part of the doubled-single accumulation vector.
*> \endverbatim
*>
*> \param[in] W
*> \verbatim
*>          W is COMPLEX*16 array, dimension (N)
*>            The vector to be added.
*> \endverbatim
*
*  Authors:
*  ========
*
*> \author Univ. of Tennessee
*> \author Univ. of California Berkeley
*> \author Univ. of Colorado Denver
*> \author NAG Ltd.
*
*> \date December 2016
*
*> \ingroup complex16OTHERcomputational
*
*  =====================================================================
      SUBROUTINE ZLA_WWADDW( N, X, Y, W )
*
*  -- LAPACK computational routine (version 3.7.0) --
*  -- LAPACK is a software package provided by Univ. of Tennessee,    --
*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
*     December 2016
*
*     .. Scalar Arguments ..
      INTEGER            N
*     ..
*     .. Array Arguments ..
      COMPLEX*16         X( * ), Y( * ), W( * )
*     ..
*
*  =====================================================================
*
*     .. Local Scalars ..
      COMPLEX*16         S
      INTEGER            I
*     ..
*     .. Executable Statements ..
      DO 10 I = 1, N
        S = X(I) + W(I)
        S = (S + S) - S
        Y(I) = ((X(I) - S) + W(I)) + Y(I)
        X(I) = S
   10 CONTINUE
      RETURN
      END