Lines Matching defs:log
30 /* log(x)
38 * 2. Approximation of log(1+f).
39 * Let s = f/(2+f) ; based on log(1+f) = log(1+s) - log(1-s)
54 * In order to guarantee error in log below 1ulp, we compute log
56 * log(1+f) = f - s*(f - R) (if f is not too large)
57 * log(1+f) = f - (hfsq - s*(hfsq+R)). (better accuracy)
59 * 3. Finally, log(x) = k*ln2 + log(1+f).
66 * log(x) is NaN with signal if x < 0 (including -INF) ;
67 * log(+INF) is +INF; log(0) is -INF with signal;
68 * log(NaN) is that NaN with no signal.
94 log (double x)
106 if (((hx & 0x7fffffff) | lx) == 0) /* log(+-0) = -inf */
110 if (hx < 0) /* log(-#) = NaN */
190 } /* log */