LAPACK 3.12.1
LAPACK: Linear Algebra PACKage
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◆ sla_wwaddw()

subroutine sla_wwaddw ( integer n,
real, dimension( * ) x,
real, dimension( * ) y,
real, dimension( * ) w )

SLA_WWADDW adds a vector into a doubled-single vector.

Download SLA_WWADDW + dependencies [TGZ] [ZIP] [TXT]

Purpose:
!> !> SLA_WWADDW adds a vector W into a doubled-single vector (X, Y). !> !> This works for all extant IBM's hex and binary floating point !> arithmetic, but not for decimal. !>
Parameters
[in]N
!> N is INTEGER !> The length of vectors X, Y, and W. !>
[in,out]X
!> X is REAL array, dimension (N) !> The first part of the doubled-single accumulation vector. !>
[in,out]Y
!> Y is REAL array, dimension (N) !> The second part of the doubled-single accumulation vector. !>
[in]W
!> W is REAL array, dimension (N) !> The vector to be added. !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.

Definition at line 78 of file sla_wwaddw.f.

79*
80* -- LAPACK computational routine --
81* -- LAPACK is a software package provided by Univ. of Tennessee, --
82* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
83*
84* .. Scalar Arguments ..
85 INTEGER N
86* ..
87* .. Array Arguments ..
88 REAL X( * ), Y( * ), W( * )
89* ..
90*
91* =====================================================================
92*
93* .. Local Scalars ..
94 REAL S
95 INTEGER I
96* ..
97* .. Executable Statements ..
98*
99 DO 10 i = 1, n
100 s = x(i) + w(i)
101 s = (s + s) - s
102 y(i) = ((x(i) - s) + w(i)) + y(i)
103 x(i) = s
104 10 CONTINUE
105 RETURN
106*
107* End of SLA_WWADDW
108*
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