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SUBROUTINE SLA_WWADDW( N, X, Y, W )
*
* -- LAPACK routine (version 3.2.2) --
* -- Contributed by James Demmel, Deaglan Halligan, Yozo Hida and --
* -- Jason Riedy of Univ. of California Berkeley. --
* -- June 2010 --
*
* -- LAPACK is a software package provided by Univ. of Tennessee, --
* -- Univ. of California Berkeley and NAG Ltd. --
*
IMPLICIT NONE
* ..
* .. Scalar Arguments ..
INTEGER N
* ..
* .. Array Arguments ..
REAL X( * ), Y( * ), W( * )
* ..
*
* 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
* arithmetics, but not for decimal.
*
* Arguments
* =========
*
* N (input) INTEGER
* The length of vectors X, Y, and W.
*
* X (input/output) REAL array, dimension (N)
* The first part of the doubled-single accumulation vector.
*
* Y (input/output) REAL array, dimension (N)
* The second part of the doubled-single accumulation vector.
*
* W (input) REAL array, dimension (N)
* The vector to be added.
*
* =====================================================================
*
* .. Local Scalars ..
REAL 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
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