function %fibonacci(i32) -> i32 {
block0(v0: i32):
    v1 = icmp_imm ule v0, 2
    v2 = iconst.i32 1
    ; handle base case, n <= 2
    brif v1, block3(v2), block1(v0, v2)

block1(v4: i32, v5:i32):
    v6 = iconst.i32 1
    v7 = iadd_imm v4, -2
    jump block2(v7, v5, v6)

block2(v10: i32, v11: i32, v12: i32): ; params: n, fib(n-1), fib(n-2)
    v13 = iadd v11, v12
    v14 = iadd_imm v10, -1
    v15 = icmp_imm eq v14, 0
    brif v15, block3(v13), block2(v14, v13, v11)

block3(v20: i32): ; early return and end of loop
    return v20
}