Zig 0.17.0-dev (Split by item)

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cosq

cos.cosq

pub fn cosq(x: f128) callconv(.c) f128

File

lib/compiler_rt/cos.zig:150

Code

pub fn cosq(x: f128) callconv(.c) f128 {
    const se = ld.signExponent(x) & 0x7fff;
    if (se == 0x7fff) {
        return x - x;
    }

    if (@abs(x) < trig.pi_4) {
        if (se < 0x3fff - math.floatMantissaBits(f128)) {
            // raise inexact if x!=0
            return 1.0 + x;
        }
        return trig.cosq(x, 0.0);
    }

    var y: [2]f128 = undefined;
    const n = rem_pio2l(f128, x, &y);
    return switch (n & 3) {
        0 => trig.cosq(y[0], y[1]),
        1 => -trig.sinq(y[0], y[1], 1),
        2 => -trig.cosq(y[0], y[1]),
        else => trig.sinq(y[0], y[1], 1),
    };
}