nextafter.rs - source
Description: Source of the Rust file `/Users/erlendbasso/.cargo/registry/src/github.com-1ecc6299db9ec823/libm-0.2.6/src/math/nextafter.rs`.
Keywords: rust, rustlang, rust-lang

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    #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
    pub fn nextafter(x: f64, y: f64) -> f64 {
        if x.is_nan() || y.is_nan() {
            return x + y;
        }

        let mut ux_i = x.to_bits();
        let uy_i = y.to_bits();
        if ux_i == uy_i {
            return y;
        }

        let ax = ux_i & !1_u64 / 2;
        let ay = uy_i & !1_u64 / 2;
        if ax == 0 {
            if ay == 0 {
                return y;
            }
            ux_i = (uy_i & 1_u64 << 63) | 1;
        } else if ax > ay || ((ux_i ^ uy_i) & 1_u64 << 63) != 0 {
            ux_i -= 1;
        } else {
            ux_i += 1;
        }

        let e = ux_i.wrapping_shr(52 & 0x7ff);
        // raise overflow if ux.f is infinite and x is finite
        if e == 0x7ff {
            force_eval!(x + x);
        }
        let ux_f = f64::from_bits(ux_i);
        // raise underflow if ux.f is subnormal or zero
        if e == 0 {
            force_eval!(x * x + ux_f * ux_f);
        }
        ux_f
    }