56   int i, k, hx;  in log2()  local
60   hx = __HI (x); /* high word of x */  in log2()
64   if (hx < 0x00100000)  in log2()
66     if (((hx & 0x7fffffff) | lx) == 0)  in log2()
70     if (hx < 0)  in log2()
76     hx = __HI (x); /* high word of x */  in log2()
78   if (hx >= 0x7ff00000)  in log2()
82   if (hx == 0x3ff00000 && lx == 0)  in log2()
86   k += (hx >> 20) - 1023;  in log2()
87   hx &= 0x000fffff;  in log2()
88   i = (hx + 0x95f64) & 0x100000;  in log2()
90   temp.as_int.hi = hx | (i ^ 0x3ff00000); /* normalize x or x/2 */  in log2()