Constant EXP_C0 

pub const EXP_C0: f32 = 0.999_999_4;

Minimax coefficients for e^b - 1 on [-ln2/2, ln2/2]: 0x1.ffffecp-1, 0x1.fffdb6p-2, 0x1.555e66p-3, 0x1.573e2ep-5, 0x1.0e4020p-7.