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.

tan

tan.tan

pub fn tan(x: f64) callconv(.c) f64

File

lib/compiler_rt/tan.zig:93

Code

pub fn tan(x: f64) callconv(.c) f64 {
    var ix = @as(u64, @bitCast(x)) >> 32;
    ix &= 0x7fffffff;

    // |x| ~< pi/4
    if (ix <= 0x3fe921fb) {
        if (ix < 0x3e400000) { // |x| < 2**-27
            // raise inexact if x!=0 and underflow if subnormal
            if (compiler_rt.want_float_exceptions) {
                if (ix < 0x00100000) {
                    mem.doNotOptimizeAway(x / 0x1p120);
                } else {
                    mem.doNotOptimizeAway(x + 0x1p120);
                }
            }
            return x;
        }
        return kernel.tan(x, 0.0, false);
    }

    // tan(Inf or NaN) is NaN
    if (ix >= 0x7ff00000) {
        return x - x;
    }

    var y: [2]f64 = undefined;
    const n = rem_pio2(x, &y);
    return kernel.tan(y[0], y[1], n & 1 != 0);
}