floorl
extern long double floorl(long double x);
px = floorl(LOG2E * x + 0.5);
px = floorl(0.5 + x / xx);
x = 2.0*(x - floorl(x)); /* x mod 2.0 */
w = floorl(y);
ya = floorl(0.5 * ya);
if (iyflg && floorl(x) == x && fabsl(y) < 32768.0) {
t = floorl(t);
p = floorl(q);
if (0.5 * p == floorl(q * 0.5))