Return to dla_wwaddw.f CVS log

Up to [local] / rpl / lapack / lapack

Cohérence Lapack.

    1: *> \brief \b DLA_WWADDW adds a vector into a doubled-single vector.
    2: *
    3: *  =========== DOCUMENTATION ===========
    4: *
    5: * Online html documentation available at 
    6: *            http://www.netlib.org/lapack/explore-html/ 
    7: *
    8: *> \htmlonly
    9: *> Download DLA_WWADDW + dependencies 
   10: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dla_wwaddw.f"> 
   11: *> [TGZ]</a> 
   12: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dla_wwaddw.f"> 
   13: *> [ZIP]</a> 
   14: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dla_wwaddw.f"> 
   15: *> [TXT]</a>
   16: *> \endhtmlonly 
   17: *
   18: *  Definition:
   19: *  ===========
   20: *
   21: *       SUBROUTINE DLA_WWADDW( N, X, Y, W )
   22: * 
   23: *       .. Scalar Arguments ..
   24: *       INTEGER            N
   25: *       ..
   26: *       .. Array Arguments ..
   27: *       DOUBLE PRECISION   X( * ), Y( * ), W( * )
   28: *       ..
   29: *  
   30: *
   31: *> \par Purpose:
   32: *  =============
   33: *>
   34: *> \verbatim
   35: *>
   36: *>    DLA_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: *>    arithmetics, 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 DOUBLE PRECISION 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 DOUBLE PRECISION 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 DOUBLE PRECISION 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: *
   77: *> \date September 2012
   78: *
   79: *> \ingroup doubleOTHERcomputational
   80: *
   81: *  =====================================================================
   82:       SUBROUTINE DLA_WWADDW( N, X, Y, W )
   83: *
   84: *  -- LAPACK computational routine (version 3.4.2) --
   85: *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
   86: *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
   87: *     September 2012
   88: *
   89: *     .. Scalar Arguments ..
   90:       INTEGER            N
   91: *     ..
   92: *     .. Array Arguments ..
   93:       DOUBLE PRECISION   X( * ), Y( * ), W( * )
   94: *     ..
   95: *
   96: *  =====================================================================
   97: *
   98: *     .. Local Scalars ..
   99:       DOUBLE PRECISION   S
  100:       INTEGER            I
  101: *     ..
  102: *     .. Executable Statements ..
  103: *
  104:       DO 10 I = 1, N
  105:         S = X(I) + W(I)
  106:         S = (S + S) - S
  107:         Y(I) = ((X(I) - S) + W(I)) + Y(I)
  108:         X(I) = S
  109:  10   CONTINUE
  110:       RETURN
  111:       END