- uint32_t low;
-
- GET_LOW_WORD(low, x);
- if (ix > 0x7ff00000 ||
- (ix == 0x7ff00000 && low != 0)) /* NaN */
- return x+x;
- if (hx > 0)
- return atanhi[3] + *(volatile double *)&atanlo[3];
- else
- return -atanhi[3] - *(volatile double *)&atanlo[3];