[Openmcl-devel] Wow, this is so not what I expected

[Ron Garret]

Welcome to Clozure Common Lisp Version 1.10-r16479M  (DarwinX8664)!

? (defun foo1 (n)
  (if (<= n 0) 0 (foo1 (1- n))))
FOO1

? (defun foo2 (n)
  (labels ((foo (n) (if (<= n 0) 0 (foo (1- n)))))
    (foo n)))
FOO2

? (disassemble 'foo1)
;;; (defun foo1 (n) (if (<= n 0) 0 (foo1 (1- n))))
L0
    (leaq (@ (:^ L0) (% rip)) (% fn))       ;     [0]
    (cmpl ($ 8) (% nargs))                  ;     [7]
    (jne L141)                              ;    [10]
    (pushq (% rbp))                         ;    [16]
    (movq (% rsp) (% rbp))                  ;    [17]
    (pushq (% save0))                       ;    [20]
    (movq (% arg_z) (% save0))              ;    [22]

;;; (<= n 0)
L25
    (movq (% save0) (% arg_y))              ;    [25]
    (testb ($ 7) (% arg_y.b))               ;    [28]
    (jne L41)                               ;    [32]
    (testq (% arg_y) (% arg_y))             ;    [34]
    (jle L66)                               ;    [37]
    (jmp L72)                               ;    [39]
L41
    (xorl (% arg_z.l) (% arg_z.l))          ;    [41]
    (nop)                                   ;    [43]
    (callq (@ .SPBUILTIN-LE))               ;    [46]
    (leaq (@ (:^ L0) (% rip)) (% fn))       ;    [53]
    (cmpb ($ 11) (% arg_z.b))               ;    [60]
    (je L72)                                ;    [64]

;;; (if (<= n 0) 0 (foo1 (1- n)))
L66
    (xorl (% arg_z.l) (% arg_z.l))          ;    [66]
    (popq (% save0))                        ;    [68]
    (leaveq)                                ;    [70]
    (retq)                                  ;    [71]

;;; (1- n)
L72
    (movq (% save0) (% arg_z))              ;    [72]
    (testb ($ 7) (% arg_z.b))               ;    [75]
    (jne L110)                              ;    [79]
    (addq ($ -8) (% arg_z))                 ;    [81]
    (jno L132)                              ;    [85]
    (nop)                                   ;    [87]
    (nop)                                   ;    [91]
    (callq (@ .SPFIX-OVERFLOW))             ;    [94]
    (leaq (@ (:^ L0) (% rip)) (% fn))       ;   [101]
    (jmp L132)                              ;   [108]
L110
    (movq ($ -8) (% arg_y))                 ;   [110]
    (nop)                                   ;   [117]
    (callq (@ .SPBUILTIN-PLUS))             ;   [118]
    (leaq (@ (:^ L0) (% rip)) (% fn))       ;   [125]
L132
    (movq (% arg_z) (% save0))              ;   [132]

;;; (foo1 (1- n))
    (jmp L25)                               ;   [135]

;;; #<no source text>
L141
    (uuo-error-wrong-number-of-args)        ;   [141]
NIL

? (disassemble 'foo2)
;;; (defun foo2 (n) (labels ((foo (n) (if (<= n 0) 0 (foo (1- n))))) (foo n)))
L0
    (leaq (@ (:^ L0) (% rip)) (% fn))       ;     [0]
    (cmpl ($ 8) (% nargs))                  ;     [7]
    (jne L45)                               ;    [10]
    (pushq (% rbp))                         ;    [12]
    (movq (% rsp) (% rbp))                  ;    [13]
    (pushq (% arg_z))                       ;    [16]

;;; (foo n)
    (movl ($ 8) (% nargs))                  ;    [17]
    (movq (@ '#<Compiled-function (:INTERNAL FOO FOO2) (Non-Global)  #x30200110BE6F> (% fn)) (% temp0)) ;    [22]
    (leaveq)                                ;    [29]
    (movq (% fn) (% temp1))                 ;    [30]
    (movq (% temp0) (% fn))                 ;    [33]
    (jmpq (% fn))                           ;    [36]

;;; #<no source text>
L45
    (uuo-error-wrong-number-of-args)        ;    [45]
NIL