Lines Matching refs:tanh
16 /* Tanh(x)
22 * 0. tanh(x) is defined to be -----------
25 * 1. reduce x to non-negative by tanh(-x) = -tanh(x).
26 * 2. 0 <= x < 2**-28 : tanh(x) := x with inexact if x != 0
28 * 2**-28 <= x < 1 : tanh(x) := -----; t = expm1(-2x)
31 * 1 <= x < 22 : tanh(x) := 1 - -----; t = expm1(2x)
33 * 22 <= x <= INF : tanh(x) := 1.
36 * tanh(NaN) is NaN;
37 * only tanh(0)=0 is exact for finite argument.
46 tanh(double x)
56 if (jx>=0) return one/x+one; /* tanh(+-inf)=+-1 */
57 else return one/x-one; /* tanh(NaN) = NaN */
63 if(huge+x>one) return x; /* tanh(tiny) = tiny with inexact */
