50  *	11. -0 ** (+anything except 0, NAN, odd integer)  is +0
147   long double z, ax, z_h, z_l, p_h, p_l;  in powl()  local
236   ax = fabsl (x);  in powl()
242 	  z = ax;		/*x is +-0,+-inf,+-1 */  in powl()
286       ax *= two113;  in powl()
288       o.value = ax;  in powl()
306   o.value = ax;  in powl()
308   ax = o.value;  in powl()
311   u = ax - bp[k];		/* bp[0]=1.0, bp[1]=1.5 */  in powl()
312   v = one / (ax + bp[k]);  in powl()
320   /* t_h=ax+bp[k] High */  in powl()
321   t_h = ax + bp[k];  in powl()
326   t_l = ax - (t_h - bp[k]);  in powl()
328   /* compute log(ax) */  in powl()
353   /* log2(ax) = (s+..)*2/(3*log2) = n + dp_h + z_h + z_l */  in powl()