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#![feature(const_panic)]
#![no_std]
#![allow(clippy::manual_range_contains)]
mod macros;
mod serde_common;
use core::num::NonZeroUsize;
pub use serde_common::*;
pub const BITS: usize = usize::BITS as usize;
pub const MAX: usize = usize::MAX;
#[inline]
#[track_caller]
pub const fn bw(bw: usize) -> NonZeroUsize {
match NonZeroUsize::new(bw) {
None => {
panic!("Tried to construct an invalid bitwidth of 0 using the `awint::bw` function")
}
Some(bw) => bw,
}
}
#[inline]
pub const fn extra(bw: NonZeroUsize) -> usize {
bw.get() & (BITS - 1)
}
#[inline]
pub const fn digits(bw: NonZeroUsize) -> usize {
bw.get().wrapping_shr(BITS.trailing_zeros())
}
#[inline]
pub const fn regular_digits(bw: NonZeroUsize) -> usize {
bw.get()
.wrapping_shr(BITS.trailing_zeros())
.wrapping_add((extra(bw) != 0) as usize)
}
#[inline]
pub const fn widen_add(x: usize, y: usize, z: usize) -> (usize, usize) {
let (sum, carry0) = x.overflowing_add(y);
let (sum, carry1) = sum.overflowing_add(z);
(sum, (carry0 as usize) + (carry1 as usize))
}
macro_rules! widen_mul_add_internal {
($x:ident, $y:ident, $z:ident; 128 => $other:block $($bits:expr, $uD:ident);*;) => {
match BITS {
$(
$bits => {
let tmp = ($x as $uD).wrapping_mul($y as $uD).wrapping_add($z as $uD);
(tmp as usize, tmp.wrapping_shr($bits) as usize)
}
)*
128 => $other
_ => panic!("Unsupported pointer size"),
}
};
}
#[inline]
pub const fn widen_mul_add(x: usize, y: usize, z: usize) -> (usize, usize) {
widen_mul_add_internal!(
x, y, z;
128 => {
let lhs_lo = x as u64;
let rhs_lo = y as u64;
let lhs_hi = (x.wrapping_shr(64)) as u64;
let rhs_hi = (y.wrapping_shr(64)) as u64;
let tmp0 = (lhs_lo as u128).wrapping_mul(rhs_lo as u128);
let tmp1 = (lhs_lo as u128).wrapping_mul(rhs_hi as u128);
let tmp2 = (lhs_hi as u128).wrapping_mul(rhs_lo as u128);
let tmp3 = (lhs_hi as u128).wrapping_mul(rhs_hi as u128);
let (mul0, carry0) = tmp0.overflowing_add(tmp1.wrapping_shl(64));
let (mul0, carry1) = mul0.overflowing_add(tmp2.wrapping_shl(64));
let (mul0, carry2) = mul0.overflowing_add(z as u128);
let mul1 = tmp3
.wrapping_add(tmp1.wrapping_shr(64))
.wrapping_add(tmp2.wrapping_shr(64))
.wrapping_add(carry0 as u128)
.wrapping_add(carry1 as u128)
.wrapping_add(carry2 as u128);
(mul0 as usize, mul1 as usize)
}
8, u16;
16, u32;
32, u64;
64, u128;
)
}
macro_rules! dd_division_internal {
($duo:ident, $div:ident; $($bits:expr, $uD:ident);*;) => {
match BITS {
$(
$bits => {
let duo = $duo.0 as $uD | (($duo.1 as $uD) << $bits);
let div = $div.0 as $uD | (($div.1 as $uD) << $bits);
let tmp0 = duo.wrapping_div(div);
let tmp1 = duo.wrapping_rem(div);
(
(
tmp0 as usize,
(tmp0 >> $bits) as usize,
),
(
tmp1 as usize,
(tmp1 >> $bits) as usize,
)
)
}
)*
_ => panic!("Unsupported pointer size"),
}
};
}
#[inline]
pub const fn dd_division(
duo: (usize, usize),
div: (usize, usize),
) -> ((usize, usize), (usize, usize)) {
dd_division_internal!(
duo, div;
8, u16;
16, u32;
32, u64;
64, u128;
)
}