    const std = @import("../std.zig");
    const builtin = @import("builtin");
    const math = std.math;
    const meta = std.meta;
    const expect = std.testing.expect;

    pub fn isNan(x: anytype) bool {
        return x != x;
    }

    /// TODO: LLVM is known to miscompile on some architectures to quiet NaN -
    ///       this is tracked by https://github.com/ziglang/zig/issues/14366
    pub fn isSignalNan(x: anytype) bool {
        const T = @TypeOf(x);
        const U = meta.Int(.unsigned, @bitSizeOf(T));
        const quiet_signal_bit_mask = 1 << (math.floatFractionalBits(T) - 1);
        return isNan(x) and (@as(U, @bitCast(x)) & quiet_signal_bit_mask == 0);
    }

    test "math.isNan" {
        inline for ([_]type{ f16, f32, f64, f80, f128, c_longdouble }) |T| {
            try expect(isNan(math.nan(T)));
            try expect(isNan(-math.nan(T)));
            try expect(isNan(math.snan(T)));
            try expect(!isNan(@as(T, 1.0)));
            try expect(!isNan(@as(T, math.inf(T))));
        }
    }

    test "math.isSignalNan" {
        inline for ([_]type{ f16, f32, f64, f80, f128, c_longdouble }) |T| {
            // TODO: Signalling NaN values get converted to quiet NaN values in

            //       some cases where they shouldn't such that this can fail.

            //       See https://github.com/ziglang/zig/issues/14366

            // try expect(isSignalNan(math.snan(T)));

            try expect(!isSignalNan(math.nan(T)));
            try expect(!isSignalNan(@as(T, 1.0)));
            try expect(!isSignalNan(math.inf(T)));
        }
    }