function gamr (x)
  c july 1977 edition.  w. fullerton, c3, los alamos scientific lab.
  c this routine, not gamma(x), should be the fundamental one.
  c
        external  gamma
  c
        gamr = 0.0
        if (x.le.0.0 .and. aint(x).eq.x) return
  c
        call entsrc (irold, 1)
        if (abs(x).gt.10.0) go to 10
        gamr = 1.0/gamma(x)
        call erroff
        call entsrc (ir, irold)
        return
  c
   10   call algams (x, alngx, sgngx)
        call erroff
        call entsrc (ir, irold)
        gamr = sgngx * exp(-alngx)
        return
  c
        end