Function regalloc_hot_loop_is_substantially_faster

tests/integration/regalloc.rs:127–149

()

#[test]
fn regalloc_hot_loop_is_substantially_faster() {
    // A tight arithmetic loop is the allocator's target workload; require a
    // real win, not statistical noise.
    let ((_, base_cycles), (_, alloc_cycles)) = assert_equivalent(
        r#"
main: () -> i32 {
    acc: i64 = 0
    i: i64 = 0
    while i < 20000 {
        acc = acc + i * 3 - (i / 2)
        i = i + 1
    }
    return (acc % 100) as i32
}
"#,
    );
    println!("hot loop cycles: {base_cycles} -> {alloc_cycles}");
    let saved = base_cycles.saturating_sub(alloc_cycles);
    assert!(
        saved * 4 >= base_cycles,
        "hot loop should run at least 25% faster: {base_cycles} -> {alloc_cycles}"
    );
}

#[test]
fn regalloc_recursion_preserves_callee_saved_values() {