impressed with llvm, again

Testing out pattern matching against constants, I wrote the following silly function:

(define thing
  0 1 -> 2
  0 y -> 3
  1 0 -> 4
  1 x -> (+ x 5)
  y z -> (+ y z)
  )
(thing 10 20)

Which turned into a nice set of if statements, doing 4 tests in total. Not bad. But I was curious to see what kind of asm LLVM would generate for it.

_vm:
Leh_func_begin7:
        pushq   %rbp
Llabel13:
        movq    %rsp, %rbp
Llabel14:
        movq    _heap0(%rip), %rax
        movq    $772, (%rax)
        movq    $10, 8(%rax)
        movq    $10, 16(%rax)
        movq    $1, 24(%rax)
        movl    $61, %eax
        popq    %rbp
        ret
Leh_func_end7:

Huh. So that bit there at the very end, "movl $61, %eax". Yeah. That's the answer, "30". Even with all the tagging/untagging, registers, embedded if statements, etc... LLVM still optimized the entire program away to a constant. Nice.