Re: Optimizer? What optimizer?

[Daniel Colascione]

On 6/6/11 7:33 PM, Daniel Colascione wrote:
> Is there some fundamental reason defsubst does so poorly here compared
> to defmacro?
> 
> ---
> [snip stupidity]

What I meant was this:

(defmacro foo-macro (a b)
  `(if ,a
       ,b
     (1+ ,b)))

(defun bar-macro (b)
  (foo-macro t b))

(defun qux-macro (b)
  (foo-macro nil b))

;; byte code for bar-macro:
;;   args: (b)
;; 0       varref    b
;; 1       return
;;
;; byte code for qux-macro:
;;   args: (b)
;; 0       varref    b
;; 1       add1
;; 2       return
;;

(defsubst foo-subst (a b)
  (if a
      b
    (1+ b)))

(defun bar-subst (b)
  (foo-subst t b))

(defun qux-subst (b)
  (foo-subst nil b))

;; byte code for bar-subst:
;;   args: (b)
;; 0       constant  t
;; 1       varref    b
;; 2       varbind   b
;; 3       dup
;; 4       varbind   a
;; 5       goto-if-nil 1
;; 8       varref    b
;; 9       goto      2
;; 12:1    varref    b
;; 13      add1
;; 14:2    unbind    2
;; 15      return
;;

;; byte code for qux-subst:
;;   args: (b)
;; 0       constant  nil
;; 1       varref    b
;; 2       varbind   b
;; 3       dup
;; 4       varbind   a
;; 5       goto-if-nil 1
;; 8       varref    b
;; 9       goto      2
;; 12:1    varref    b
;; 13      add1
;; 14:2    unbind    2
;; 15      return
;;

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