LAPACK 3.12.0 LAPACK: Linear Algebra PACKage
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2*
3* =========== DOCUMENTATION ===========
4*
5* Online html documentation available at
6* http://www.netlib.org/lapack/explore-html/
7*
8*> \htmlonly
11*> [TGZ]</a>
13*> [ZIP]</a>
15*> [TXT]</a>
16*> \endhtmlonly
17*
18* Definition:
19* ===========
20*
21* SUBROUTINE SLA_WWADDW( N, X, Y, W )
22*
23* .. Scalar Arguments ..
24* INTEGER N
25* ..
26* .. Array Arguments ..
27* REAL X( * ), Y( * ), W( * )
28* ..
29*
30*
31*> \par Purpose:
32* =============
33*>
34*> \verbatim
35*>
36*> SLA_WWADDW adds a vector W into a doubled-single vector (X, Y).
37*>
38*> This works for all extant IBM's hex and binary floating point
39*> arithmetic, but not for decimal.
40*> \endverbatim
41*
42* Arguments:
43* ==========
44*
45*> \param[in] N
46*> \verbatim
47*> N is INTEGER
48*> The length of vectors X, Y, and W.
49*> \endverbatim
50*>
51*> \param[in,out] X
52*> \verbatim
53*> X is REAL array, dimension (N)
54*> The first part of the doubled-single accumulation vector.
55*> \endverbatim
56*>
57*> \param[in,out] Y
58*> \verbatim
59*> Y is REAL array, dimension (N)
60*> The second part of the doubled-single accumulation vector.
61*> \endverbatim
62*>
63*> \param[in] W
64*> \verbatim
65*> W is REAL array, dimension (N)
66*> The vector to be added.
67*> \endverbatim
68*
69* Authors:
70* ========
71*
72*> \author Univ. of Tennessee
73*> \author Univ. of California Berkeley
74*> \author Univ. of Colorado Denver
75*> \author NAG Ltd.
76*
78*
79* =====================================================================
80 SUBROUTINE sla_wwaddw( N, X, Y, W )
81*
82* -- LAPACK computational routine --
83* -- LAPACK is a software package provided by Univ. of Tennessee, --
84* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
85*
86* .. Scalar Arguments ..
87 INTEGER N
88* ..
89* .. Array Arguments ..
90 REAL X( * ), Y( * ), W( * )
91* ..
92*
93* =====================================================================
94*
95* .. Local Scalars ..
96 REAL S
97 INTEGER I
98* ..
99* .. Executable Statements ..
100*
101 DO 10 i = 1, n
102 s = x(i) + w(i)
103 s = (s + s) - s
104 y(i) = ((x(i) - s) + w(i)) + y(i)
105 x(i) = s
106 10 CONTINUE
107 RETURN
108*