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// Copyright © 2026 Mikhail Hogrefe
//
// This file is part of Malachite.
//
// Malachite is free software: you can redistribute it and/or modify it under the terms of the GNU
// Lesser General Public License (LGPL) as published by the Free Software Foundation; either version
// 3 of the License, or (at your option) any later version. See <https://www.gnu.org/licenses/>.
use crate::num::arithmetic::mul_add_mul::{
Wide, mul_add_mul_wide_signed, mul_add_mul_wide_unsigned,
};
use crate::num::arithmetic::traits::{SaturatingMulAddMul, SaturatingMulAddMulAssign};
macro_rules! impl_saturating_mul_add_mul {
($t:ident, $wide:ident) => {
impl SaturatingMulAddMul for $t {
type Output = $t;
/// Adds the products of two pairs of numbers, saturating at the numeric bounds instead
/// of overflowing.
///
/// $$
/// f(x, y, z, w) = \\begin{cases}
/// xy + zw & \\text{if} \\quad m \\leq xy + zw \\leq M \\\\
/// M & \\text{if} \\quad xy + zw > M \\\\
/// m & \\text{if} \\quad xy + zw < m,
/// \\end{cases}
/// $$
/// where $m$ is `Self::MIN` and $M$ is `Self::MAX`.
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// See [here](super::saturating_mul_add_mul#saturating_mul_add_mul).
#[inline]
fn saturating_mul_add_mul(self, y: $t, z: $t, w: $t) -> $t {
match $wide(self, y, z, w, false) {
Wide::Fits(v) => v,
Wide::Above => $t::MAX,
Wide::Below => $t::MIN,
}
}
}
impl SaturatingMulAddMulAssign for $t {
/// Adds the products of two pairs of numbers, in place, saturating at the numeric
/// bounds instead of overflowing.
///
/// $$
/// x \\gets \\begin{cases}
/// xy + zw & \\text{if} \\quad m \\leq xy + zw \\leq M \\\\
/// M & \\text{if} \\quad xy + zw > M \\\\
/// m & \\text{if} \\quad xy + zw < m,
/// \\end{cases}
/// $$
/// where $m$ is `Self::MIN` and $M$ is `Self::MAX`.
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// See [here](super::saturating_mul_add_mul#saturating_mul_add_mul_assign).
#[inline]
fn saturating_mul_add_mul_assign(&mut self, y: $t, z: $t, w: $t) {
*self = self.saturating_mul_add_mul(y, z, w);
}
}
};
}
macro_rules! impl_saturating_mul_add_mul_unsigned {
($t:ident) => {
impl_saturating_mul_add_mul!($t, mul_add_mul_wide_unsigned);
};
}
apply_to_unsigneds!(impl_saturating_mul_add_mul_unsigned);
macro_rules! impl_saturating_mul_add_mul_signed {
($t:ident) => {
impl_saturating_mul_add_mul!($t, mul_add_mul_wide_signed);
};
}
apply_to_signeds!(impl_saturating_mul_add_mul_signed);