speeding up Maxima by low-level hacking of simplifier

This is not quite perfected, but in case someone cares to look at it
with me, I changed eqtest, a program in the source file simp.lisp.
On my machine, with GCL Maxima 5.25.1 took 550 seconds (run - garbage 
collect)
to do run_testsuite(time=true).

After the change, 488 seconds.

The answers to all the 9060 tests was the same except for 2, reported as:
Errors found in 
C:/PROGRA~1/MAXIMA~1.1-G/share/maxima/5.25.1/tests/rtest_hypgeo.mac, 
problems:
(126 190)

I'm trying to figure out why.


If you want to discuss this, ask/study..


;; here is the new code..
;; think about it.

(defun eqtest(x check &aux head )
   (cond ((atom x) x)

     ((eq (setf head (caar x)) 'rat) x )

     ((and (eq head (caar check))  ;; check for structural equality 
except maybe simp flag
           (equal (cdr x) (cdr check)))
      (put-in-simp check))

     ((memq 'array (cdar check))
      (put-in-simp-arr x))
     (t
      (put-in-simp x ))))


(defun put-in-simp(w &aux flag)  ;; w is a cons, e.g. ((mplus) $y $x).
   (cond ((member 'simp (cdar w) :test #'eq)w) ; already has simp flag
     (t
      (cons
       ;; compute head of expression
       (cond ((cdar w) ;; there is some flag, not simp. maybe array
          (cons (caar w)(cons 'simp (cdar w))))
         ((eq (setf flag (caar w)) 'mplus) '(mplus simp)) ;; maybe 
faster than checking prop list
         ((eq flag 'mtimes) '(mtimes simp))
         ((eq flag 'mexpt) '(mexpt simp))

         (t (if(setf flag (get flag 'msimpind)) flag ; if msimpind, use it
              (setf (get (caar w) 'msimpind)(cons (caar w) '(simp)))))) 
; if no msimpind flag, make one.
       (cdr w)))))

(defun put-in-simp-arr(w &aux flag)
   (cons  (list(caar w) 'simp 'array) (cdr w)))