#bit-manipulation #bits #overflow #width #bit #twos-complement

bitmath

Tools for arbitrary-sized bitwise arithmetic

2 releases

0.0.2 Nov 4, 2022
0.0.1 Apr 21, 2022

#787 in Math

MIT license

15KB
254 lines

bitmath

Tools for arbitrary-width bitwise arithmetic. Originally designed for writing fantasy console/cpu emulators.

Unstable. WIP. Use at your own risk.

Bits<N>

The heart of bitmath. Bits is a generically sized bit vector with support for bitwise operations and arithmetic (WIP).

For example, you can add a pair of 3-bit numbers and find out whether it overflowed:

let a = Bits::<3>::try_from("101").unwrap();
let b = Bits::<3>::try_from("110").unwrap();
let (result, overflowed) = a.unsigned_add(b);
println!("result: {}, overflowed: {}", result, overflowed);
// result: Bits<3>{ 011 | dec 3/3 | hex 0x3/0x3 }, overflowed: true

Or you can take a subset of Bits with conventional bitwise syntax using the bitslice! macro:

let word = Bits::<16>::try_from("1011 0001 0110 1011").unwrap();
let high_byte = bitslice!(word[15:8]);
let low_byte = bitslice!(word[7:0]);
println!("{}\n{}\n{}", word, high_byte, low_byte);
// Bits<16>{ 1011 0001 0110 1011 | dec 45419/-20117 | hex 0xb16b/-0x4e95 }
// Bits<8>{ 1011 0001 | dec 177/-79 | hex 0xb1/-0x4f }
// Bits<8>{ 0110 1011 | dec 107/107 | hex 0x6b/0x6b }

No runtime deps