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Source code

// Type your code here, or load an example.

unsafe extern "C" {
    fn write(p: *const u16);
}

#[inline(always)]
fn in_inclusive_range16(u: u16, start: u16, end: u16) -> bool {
    u.wrapping_sub(start) <= (end - start)
}

// Weirdness:
// Look for `cset` under LBB0_3 in aarch64
// and `setne` + `lea` under LBB0_4 in x86_64.
// These seem to correlate with bb2.preheader in LLVM IR.
#[unsafe(no_mangle)]
pub fn bad_loop(pending_slice: &[u16], slice: &[u16], bound: u32, other: u32) {
    // SPDX: Unicode-3.0
    // From icu_normalizer
    let mut code_unit_iter = slice.iter();
    let mut upcoming32;
    let mut trie_value: u32; // Significant even if unused!
    'fast: loop {
        if let Some(&upcoming_code_unit) = code_unit_iter.next() {
            upcoming32 = u32::from(upcoming_code_unit); // may be surrogate
            if upcoming32 < bound {
                continue 'fast;
            }
            'surrogateloop: loop {
                let surrogate_base = upcoming32.wrapping_sub(0xD800);
                if surrogate_base > (0xDFFF - 0xD800) {
                    break 'surrogateloop;
                }
                if surrogate_base <= (0xDBFF - 0xD800) {
                    let iter_backup = code_unit_iter.clone(); // This line is significant even as unused!
                    if let Some(&low) = code_unit_iter.next() {
                        if in_inclusive_range16(low, 0xDC00, 0xDFFF) { // Can't simplify this!
                            upcoming32 = (upcoming32 << 10) + u32::from(low)
                                - (((0xD800u32 << 10) - 0x10000u32) + 0xDC00u32);
                            if upcoming32 < other {
                                continue 'fast;
                            }
                            break 'surrogateloop;
                        } else {
                            // Somehow this can be commented out:
                            // code_unit_iter = iter_backup;
                        }
                    }
                }
                break 'surrogateloop;
            }

let consumed_so_far = &pending_slice[..pending_slice.len() - code_unit_iter.as_slice().len() - 1];
            unsafe{write(consumed_so_far.as_ptr())};
            break 'fast;
        }
        break;
    }
}