*> \brief \b ZAXPY
*
*  =========== DOCUMENTATION ===========
*
* Online html documentation available at 
*            http://www.netlib.org/lapack/explore-html/ 
*
*  Definition:
*  ===========
*
*       SUBROUTINE ZAXPY(N,ZA,ZX,INCX,ZY,INCY)
* 
*       .. Scalar Arguments ..
*       COMPLEX*16 ZA
*       INTEGER INCX,INCY,N
*       ..
*       .. Array Arguments ..
*       COMPLEX*16 ZX(*),ZY(*)
*       ..
*  
*
*> \par Purpose:
*  =============
*>
*> \verbatim
*>
*>    ZAXPY constant times a vector plus a vector.
*> \endverbatim
*
*  Authors:
*  ========
*
*> \author Univ. of Tennessee 
*> \author Univ. of California Berkeley 
*> \author Univ. of Colorado Denver 
*> \author NAG Ltd. 
*
*> \date November 2011
*
*> \ingroup complex16_blas_level1
*
*> \par Further Details:
*  =====================
*>
*> \verbatim
*>
*>     jack dongarra, 3/11/78.
*>     modified 12/3/93, array(1) declarations changed to array(*)
*> \endverbatim
*>
*  =====================================================================
      SUBROUTINE GAL_ZAXPY(N,ZA,ZX,INCX,ZY,INCY)
*
*  -- Reference BLAS level1 routine (version 3.4.0) --
*  -- Reference BLAS is a software package provided by Univ. of Tennessee,    --
*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
*     November 2011
*
*     .. Scalar Arguments ..
      COMPLEX*16ZA
      INTEGER INCX,INCY,N
*     ..
*     .. Array Arguments ..
      COMPLEX*16ZX(*),ZY(*)
*     ..
*
*  =====================================================================
*
*     .. Local Scalars ..
      INTEGER I,IX,IY
*     ..
*     .. External Functions ..
      DOUBLE PRECISION GAL_DCABS1
      EXTERNAL GAL_DCABS1
*     ..
      IF(N.LE.0)RETURN
      IF(GAL_DCABS1(ZA).EQ.0.0D0)RETURN
      IF(INCX.EQ.1.AND.INCY.EQ.1)THEN
*
*        code for both increments equal to 1
*
      DO I=1,N
      ZY(I)=ZY(I)+ZA*ZX(I)
      END DO 
      ELSE 
*
*        code for unequal increments or equal increments
*          not equal to 1
*
      IX=1
      IY=1
      IF(INCX.LT.0)IX=(-N+1)*INCX+1
      IF(INCY.LT.0)IY=(-N+1)*INCY+1
      DO I=1,N
      ZY(IY)=ZY(IY)+ZA*ZX(IX)
      IX=IX+INCX
      IY=IY+INCY
      END DO 
      END IF
*
      RETURN
      END 
