use core::ops;
use int::Int;
use int::LargeInt;
trait Mul: LargeInt {
fn mul(self, other: Self) -> Self {
let half_bits = Self::BITS / 4;
let lower_mask = !<<Self as LargeInt>::LowHalf>::ZERO >> half_bits;
let mut low = (self.low() & lower_mask).wrapping_mul(other.low() & lower_mask);
let mut t = low >> half_bits;
low &= lower_mask;
t += (self.low() >> half_bits).wrapping_mul(other.low() & lower_mask);
low += (t & lower_mask) << half_bits;
let mut high = Self::low_as_high(t >> half_bits);
t = low >> half_bits;
low &= lower_mask;
t += (other.low() >> half_bits).wrapping_mul(self.low() & lower_mask);
low += (t & lower_mask) << half_bits;
high += Self::low_as_high(t >> half_bits);
high += Self::low_as_high((self.low() >> half_bits).wrapping_mul(other.low() >> half_bits));
high = high
.wrapping_add(self.high().wrapping_mul(Self::low_as_high(other.low())))
.wrapping_add(Self::low_as_high(self.low()).wrapping_mul(other.high()));
Self::from_parts(low, high)
}
}
impl Mul for u64 {}
impl Mul for i128 {}
trait Mulo: Int + ops::Neg<Output = Self> {
fn mulo(self, other: Self, overflow: &mut i32) -> Self {
*overflow = 0;
let result = self.wrapping_mul(other);
if self == Self::min_value() {
if other != Self::ZERO && other != Self::ONE {
*overflow = 1;
}
return result;
}
if other == Self::min_value() {
if self != Self::ZERO && self != Self::ONE {
*overflow = 1;
}
return result;
}
let sa = self >> (Self::BITS - 1);
let abs_a = (self ^ sa) - sa;
let sb = other >> (Self::BITS - 1);
let abs_b = (other ^ sb) - sb;
let two = Self::ONE + Self::ONE;
if abs_a < two || abs_b < two {
return result;
}
if sa == sb {
if abs_a > Self::max_value().aborting_div(abs_b) {
*overflow = 1;
}
} else {
if abs_a > Self::min_value().aborting_div(-abs_b) {
*overflow = 1;
}
}
result
}
}
impl Mulo for i32 {}
impl Mulo for i64 {}
impl Mulo for i128 {}
trait UMulo: Int {
fn mulo(self, other: Self, overflow: &mut i32) -> Self {
*overflow = 0;
let result = self.wrapping_mul(other);
if self > Self::max_value().aborting_div(other) {
*overflow = 1;
}
result
}
}
impl UMulo for u128 {}
intrinsics! {
#[maybe_use_optimized_c_shim]
#[arm_aeabi_alias = __aeabi_lmul]
pub extern "C" fn __muldi3(a: u64, b: u64) -> u64 {
a.mul(b)
}
#[aapcs_on_arm]
pub extern "C" fn __multi3(a: i128, b: i128) -> i128 {
a.mul(b)
}
pub extern "C" fn __mulosi4(a: i32, b: i32, oflow: &mut i32) -> i32 {
a.mulo(b, oflow)
}
pub extern "C" fn __mulodi4(a: i64, b: i64, oflow: &mut i32) -> i64 {
a.mulo(b, oflow)
}
#[unadjusted_on_win64]
pub extern "C" fn __muloti4(a: i128, b: i128, oflow: &mut i32) -> i128 {
a.mulo(b, oflow)
}
pub extern "C" fn __rust_i128_mulo(a: i128, b: i128) -> (i128, bool) {
let mut oflow = 0;
let r = __muloti4(a, b, &mut oflow);
(r, oflow != 0)
}
pub extern "C" fn __rust_u128_mulo(a: u128, b: u128) -> (u128, bool) {
let mut oflow = 0;
let r = a.mulo(b, &mut oflow);
(r, oflow != 0)
}
}