Zig 0.17.0-dev (Split by item)

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atanh_32

atanh.atanh_32

fn atanh_32(x: f32) f32

File

lib/std/math/atanh.zig:29

Code

fn atanh_32(x: f32) f32 {
    const u = @as(u32, @bitCast(x));
    const i = u & 0x7FFFFFFF;
    const s = u >> 31;

    var y = @as(f32, @bitCast(i)); // |x|

    if (y == 1.0) {
        return math.copysign(math.inf(f32), x);
    }

    if (u < 0x3F800000 - (1 << 23)) {
        if (u < 0x3F800000 - (32 << 23)) {
            // underflow
            if (u < (1 << 23)) {
                mem.doNotOptimizeAway(y * y);
            }
        }
        // |x| < 0.5
        else {
            y = 0.5 * math.log1p(2 * y + 2 * y * y / (1 - y));
        }
    } else {
        y = 0.5 * math.log1p(2 * (y / (1 - y)));
    }

    return if (s != 0) -y else y;
}