NAME
    IEEEDPFloor -- compute Floor function of IEEE double precision number
SYNOPSIS
      x   = IEEEDPFloor(  y  );
    d0/d1               d0/d1
    double  x,y;
FUNCTION
    Calculate the largest integer less than or equal to x and return it.
    This value may have more than 32 bits of significance.
INPUTS
    y -- IEEE double precision floating point value
RESULT
    x -- IEEE double precision floating point value
BUGS
SEE ALSO
    ieeedpceil