The Lisp code pre compilation:
(let fib (fn (n)
(if (lt n 2)
n
(add (fib (sub n 1)) (fib (sub n 2))))))
(fib 4)The Lisp code after being compiled:
begin:
pi 4
jump fib
fib: | n
copy | n n
pi 2 | n n 2
jlt done | n
copy | n n
pi 1 | n n 1
sub | n n-1
call fib | n fib(n-1)
rot 1 | fib(n-1) n
pi 2 | fib(n-1) n 2
sub | fib(n-1) n-2
call fib | fib(n-1) fib(n-2)
add | fib(n)
done:
ret | fib(n)
The bytecode after having its labels removed and jumps filled with their relative versions:
pi 4
jump 1
copy
pi 2
jlt 10
copy
pi 1
sub
call -6
rot 1
pi 2
sub
call -10
add
ret
The Lisp code before being compiled:
(let is-prime-helper (fn (n i)
(if (gt (* i i) n)
1
(if (eq (mod n i) 0)
0
(is-prime-helper n (+ i 2))))))
(let is-prime (fn (n)
(if (lt n 3)
1
(if (eq (mod n 2) 0)
0
(is-prime-helper n 3)))))
(is-prime 11)The bytecode the Lisp gets compiled to:
is-prime-helper: | n i
copy | n i i
copy | n i i i
mul | n i i*i
rot 2 | i n i*i
rot 1 | i i*i n
copy | i i*i n n
rot 2 | i n i*i n
jgt iph-true | i n
copy | i n n
rot 2 | n i n
rot 1 | n n i
copy | n n i i
rot 2 | n i n i
mod | n i n%i
pi 0 | n i n%i 0
jeq iph-false | n i
pi 2 | n i+2
call is-prime-helper | is-prime-helper(n, i+2)
ret
iph-true: | n i
pop | n
pop |
pi 1 | 1
ret
iph-false: | n i
pop | n
pop |
pi 0 | 0
ret
is-prime: | n
copy | n n
pi 3 | n n 3
jlt ip-true | n
copy | n n
pi 2 | n n 2
mod | n n%2
pi 0 | n n%2 0
jeq ip-false | n
pi 3 | n 3
call is-prime-helper | is-prime-helper(n, 3)
ret
ip-true:
pop |
pi 1 | 1
ret
ip-false:
pop |
pi 0 | 0
ret