subroutine zgerc ( m, n, alpha, x, incx, y, incy, a, lda )
*     .. scalar arguments ..
      complex*16         alpha
      integer            incx, incy, lda, m, n
*     .. array arguments ..
      complex*16         a( lda, * ), x( * ), y( * )
*     ..
*
*  purpose
*  =======
*
*  zgerc  performs the rank 1 operation
*
*     a := alpha*x*conjg( y' ) + a,
*
*  where alpha is a scalar, x is an m element vector, y is an n element
*  vector and a is an m by n matrix.
*
*  parameters
*  ==========
*
*  m      - integer.
*           on entry, m specifies the number of rows of the matrix a.
*           m must be at least zero.
*           unchanged on exit.
*
*  n      - integer.
*           on entry, n specifies the number of columns of the matrix a.
*           n must be at least zero.
*           unchanged on exit.
*
*  alpha  - complex*16      .
*           on entry, alpha specifies the scalar alpha.
*           unchanged on exit.
*
*  x      - complex*16       array of dimension at least
*           ( 1 + ( m - 1 )*abs( incx ) ).
*           before entry, the incremented array x must contain the m
*           element vector x.
*           unchanged on exit.
*
*  incx   - integer.
*           on entry, incx specifies the increment for the elements of
*           x. incx must not be zero.
*           unchanged on exit.
*
*  y      - complex*16       array of dimension at least
*           ( 1 + ( n - 1 )*abs( incy ) ).
*           before entry, the incremented array y must contain the n
*           element vector y.
*           unchanged on exit.
*
*  incy   - integer.
*           on entry, incy specifies the increment for the elements of
*           y. incy must not be zero.
*           unchanged on exit.
*
*  a      - complex*16       array of dimension ( lda, n ).
*           before entry, the leading m by n part of the array a must
*           contain the matrix of coefficients. on exit, a is
*           overwritten by the updated matrix.
*
*  lda    - integer.
*           on entry, lda specifies the first dimension of a as declared
*           in the calling (sub) program. lda must be at least
*           max( 1, m ).
*           unchanged on exit.
*
*
*  level 2 blas routine.
*
*  -- written on 22-october-1986.
*     jack dongarra, argonne national lab.
*     jeremy du croz, nag central office.
*     sven hammarling, nag central office.
*     richard hanson, sandia national labs.
*