roc/compiler/builtins/bitcode/src/lib.rs

// NOTE: Editing this file on its own does nothing! The procedure for
// incorporating changes here is in this crate' README.

#![crate_type = "lib"]
#![no_std]

/// TODO replace this with a normal Inkwell build_cast call - this was just
/// used as a proof of concept for getting bitcode importing working!
#[no_mangle]
pub fn i64_to_f64_(num: i64) -> f64 {
    num as f64
}

/// Adapted from Rust's core::num module, by the Rust core team,
/// licensed under the Apache License, version 2.0 - https://www.apache.org/licenses/LICENSE-2.0
///
/// Thank you, Rust core team!
#[no_mangle]
pub fn pow_int_(mut base: i64, mut exp: i64) -> i64 {
    let mut acc = 1;

    while exp > 1 {
        if (exp & 1) == 1 {
            acc *= base;
        }
        exp /= 2;
        base *= base;
    }

    // Deal with the final bit of the exponent separately, since
    // squaring the base afterwards is not necessary and may cause a
    // needless overflow.
    if exp == 1 {
        acc *= base;
    }

    acc
}