Zig 0.17.0-dev (Split by item)

This is an example of documentation generated by ZigDoc, an alternative to Zig's built-in Auto Doc feature. See also examples in other modes/formats. The project being documented here (as the example) is the Zig library itself.

cosh64

cosh.cosh64

fn cosh64(x: f64) f64

File

lib/std/math/cosh.zig:56

Code

fn cosh64(x: f64) f64 {
    const u = @as(u64, @bitCast(x));
    const w = @as(u32, @intCast(u >> 32)) & (maxInt(u32) >> 1);
    const ax = @as(f64, @bitCast(u & (maxInt(u64) >> 1)));

    // TODO: Shouldn't need this explicit check.
    if (x == 0.0) {
        return 1.0;
    }

    // |x| < log(2)
    if (w < 0x3FE62E42) {
        if (w < 0x3FF00000 - (26 << 20)) {
            if (x != 0) {
                math.raiseInexact();
            }
            return 1.0;
        }
        const t = math.expm1(ax);
        return 1 + t * t / (2 * (1 + t));
    }

    // |x| < log(DBL_MAX)
    if (w < 0x40862E42) {
        const t = @exp(ax);
        // NOTE: If x > log(0x1p26) then 1/t is not required.
        return 0.5 * (t + 1 / t);
    }

    // |x| > log(CBL_MAX) or nan
    return expo2(ax);
}