*> \brief \b DLA_WWADDW adds a vector into a doubled-single vector. * * =========== DOCUMENTATION =========== * * Online html documentation available at * http://www.netlib.org/lapack/explore-html/ * *> \htmlonly *> Download DLA_WWADDW + dependencies *> *> [TGZ] *> *> [ZIP] *> *> [TXT] *> \endhtmlonly * * Definition: * =========== * * SUBROUTINE DLA_WWADDW( N, X, Y, W ) * * .. Scalar Arguments .. * INTEGER N * .. * .. Array Arguments .. * DOUBLE PRECISION X( * ), Y( * ), W( * ) * .. * * *> \par Purpose: * ============= *> *> \verbatim *> *> 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. *> \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 DOUBLE PRECISION array, dimension (N) *> The first part of the doubled-single accumulation vector. *> \endverbatim *> *> \param[in,out] Y *> \verbatim *> Y is DOUBLE PRECISION array, dimension (N) *> The second part of the doubled-single accumulation vector. *> \endverbatim *> *> \param[in] W *> \verbatim *> W is DOUBLE PRECISION 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. * *> \ingroup doubleOTHERcomputational * * ===================================================================== SUBROUTINE DLA_WWADDW( N, X, Y, W ) * * -- LAPACK computational routine -- * -- LAPACK is a software package provided by Univ. of Tennessee, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- * * .. Scalar Arguments .. INTEGER N * .. * .. Array Arguments .. DOUBLE PRECISION X( * ), Y( * ), W( * ) * .. * * ===================================================================== * * .. Local Scalars .. DOUBLE PRECISION 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 of DLA_WWADDW * END