dashu-int 0.6.0

Arbitrary-precision integer math library for Rust, balancing ergonomics and efficiency. Provides UBig and IBig (unsigned and signed), with small values inlined on the stack. Efficient arithmetic, modular arithmetic, and number theory (pow, ilog, gcd, gcd_ext); two's-complement bit operations; parsing and formatting in base 2-36; optional serde, rand, num-traits, rkyv, and zeroize.
Documentation 
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use crate::{arch::word::Word, primitive::WORD_BYTES, radix::DigitCase};

/// Chunk length for digit conversion.
pub const DIGIT_CHUNK_LEN: usize = WORD_BYTES;

/// Convert raw digits to ASCII.
///
/// digits must be valid
#[inline]
pub fn digit_chunk_raw_to_ascii(digits: &mut [u8; DIGIT_CHUNK_LEN], digit_case: DigitCase) {
    let mut word = Word::from_ne_bytes(*digits);

    // ALL_ONES = 0x01010101...
    const ALL_ONES: Word = Word::MAX / 0xff;

    // For digits >= 10, add 'a'-'0' or 'A'-'0' as appropriate.
    if digit_case != DigitCase::NoLetters {
        // Find digits >= 10, in parallel.
        // 0x76 + digit will have the top bit set if digit >= 10.
        // letters: 0x01 if digit >= 10.
        let letters = ((0x76 * ALL_ONES + word) >> 7) & ALL_ONES;

        word += letters * (digit_case as Word);
    }

    // Convert digits to ASCII in parallel.
    word += ALL_ONES * (b'0' as Word);

    digits.copy_from_slice(&word.to_ne_bytes());
}