LAPACK  3.10.0
LAPACK: Linear Algebra PACKage

◆ dla_wwaddw()

subroutine dla_wwaddw ( integer  N,
double precision, dimension( * )  X,
double precision, dimension( * )  Y,
double precision, dimension( * )  W 
)

DLA_WWADDW adds a vector into a doubled-single vector.

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

Purpose:
    DLA_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 DOUBLE PRECISION array, dimension (N)
            The first part of the doubled-single accumulation vector.
[in,out]Y
          Y is DOUBLE PRECISION array, dimension (N)
            The second part of the doubled-single accumulation vector.
[in]W
          W is DOUBLE PRECISION 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 80 of file dla_wwaddw.f.

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  DOUBLE PRECISION X( * ), Y( * ), W( * )
91 * ..
92 *
93 * =====================================================================
94 *
95 * .. Local Scalars ..
96  DOUBLE PRECISION 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 *
109 * End of DLA_WWADDW
110 *
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