memoize-raw.lisp

; ACL2 Version 6.4 -- A Computational Logic for Applicative Common Lisp
; Copyright (C) 2014, Regents of the University of Texas

; This version of ACL2 is a descendent of ACL2 Version 1.9, Copyright
; (C) 1997 Computational Logic, Inc.  See the documentation topic NOTE-2-0.

; This program is free software; you can redistribute it and/or modify
; it under the terms of the LICENSE file distributed with ACL2.

; This program is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
; LICENSE for more details.

; Written by:  Matt Kaufmann               and J Strother Moore
; email:       Kaufmann@cs.utexas.edu      and Moore@cs.utexas.edu
; Department of Computer Science
; University of Texas at Austin
; Austin, TX 78712 U.S.A.

; memoize-raw.lisp -- Raw lisp definitions for memoization functions, only to
; be included in the experimental HONS version of ACL2.

; The original version of this file was contributed by Bob Boyer and
; Warren A. Hunt, Jr.  The design of this system of Hash CONS,
; function memoization, and fast association lists (applicative hash
; tables) was initially implemented by Boyer and Hunt.

(in-package "ACL2")


(eval-when
 (:execute :compile-toplevel :load-toplevel)

 #-hons
 ;; [Jared]: Is there a real reason that memoization needs hons?
 (error "memoize-raw.lisp should only be included when #+hons is set.")

 ;; [Jared]: MEMOIZE IS NOT THREAD SAFE. I am getting rid of all of the locking
 ;; stuff that was here before. It was just muddying the waters and making
 ;; things harder to understand.  We'll need to think hard and do it right,
 ;; later.

 ;; One may comment out the following PUSHNEW and rebuild to get profiling
 ;; times not based upon the curious and wondrous RDTSC instruction of some x86
 ;; processors.  On a machine with several cores, the RDTSC values returned by
 ;; different cores may be slightly different, which could lead one into such
 ;; nonsense as instructions apparently executing in negative time, when timing
 ;; starts on one core and finishes on another.  To some extent we ignore such
 ;; RDTSC nonsense, but we still can report mysterious results since we have no
 ;; clue about which core we are running on in CCL.

  #+Clozure
  (when (fboundp 'ccl::rdtsc) (pushnew :RDTSC *features*))

  )




; MFIXNUM ---------------------------------------------------------------------
;
; We use the type mfixnum for counting things that are best counted in the
; trillions or more.  Mfixnums happen to coincide with regular fixnums on
; 64-bit CCL and SBCL.
;
; [Jared]: this seems fine, probably a good idea.

(defconstant most-positive-mfixnum (1- (expt 2 60)))

(deftype mfixnum ()
  `(integer ,(- -1 most-positive-mfixnum)
            ,most-positive-mfixnum))




; OUR-SYNTAX -----------------------------------------------------------------
;
; [Jared]: This is just some printing stuff.  I don't think I need/want any of
; this in the new memoize library.  But there's nothing really wrong with it.
; A big part of the complexity here was probably due to supporting the old
; compact-print/compact-read mechanism, but we just don't need that anymore
; with serialize.

(defmacro our-syntax (&rest args)

  "OUR-SYNTAX is similar to Common Lisp's WITH-STANDARD-IO-SYNTAX.
  The settings in OUR-SYNTAX are oriented towards reliable, standard,
  vanilla, mechanical reading and printing, and less towards human
  readability.

  Please, before changing the following, consider existing uses of
  this macro insofar as the changes might impact reliable, standard,
  vanilla, mechanical printing.  Especially consider
  COMPACT-PRINT-FILE.  Consider using OUR-SYNTAX-NICE."

; We use the *ACL2-PACKAGE* and the *ACL2-READTABLE* because we use
; them almost all the time in our code.

  `(with-standard-io-syntax

; Note for GCL:
; As of late May 2013, with-standard-io-syntax seems to work properly in ANSI
; GCL.  If necessary one could use our-with-standard-io-syntax here, but better
; would be to use an up-to-date ANSI GCL.

    (let ((*package* *acl2-package*)
          (*readtable* *acl2-readtable*))
      ,@args)))

(defmacro our-syntax-nice (&rest args)
  ;; OUR-SYNTAX-NICE offers slightly more pleasant human readabilty.
  `(our-syntax
    (setq *print-case*                 :downcase)
    (setq *print-pretty*               t)
    (setq *print-readably*             nil)
    (setq *print-right-margin*         70)
    (setq *print-miser-width*          100)
    ,@args))

(defmacro our-syntax-brief (&rest args)
  ;; Within OUR-SYNTAX-BRIEF printing may be greatly abbreviated.
  `(our-syntax-nice
    (setq *print-length* 10)
    (setq *print-level* 5)
    (setq *print-lines* 10)
    ,@args))


(defmacro ofn (&rest r) ; For forming strings.
  `(our-syntax (format nil ,@r)))

(defun-one-output ofnum (n) ; For forming numbers.
  (check-type n number)
  (if (= n 0) (setq n 0))
  (our-syntax
   (cond ((typep n '(integer -99 999))
          (format nil "~8d" n))
         ((or (< -1000 n -1/100)
              (< 1/100 n 1000))
          (format nil "~8,2f" n))
         (t (format nil "~8,2e" n)))))

(defmacro ofni (&rest r) ; For forming symbols in package ACL2.
  `(our-syntax (intern (format nil ,@r) *acl2-package*)))

(defmacro ofnm (&rest r) ; For forming uninterned symbols.
  `(our-syntax (make-symbol (format nil ,@r))))

(defmacro oft (&rest r) ; For writing to *standard-output*.
  `(progn (format t ,@r)
          (force-output *standard-output*)))

(defmacro oftr (&rest r) ; For writing to *trace-output*.
  `(progn (format *trace-output* ,@r)
          (force-output *trace-output*)))



; Number of arguments ---------------------------------------------------------
;
; [Jared]: dealt with this in books/memoize/numargs

(defv *number-of-arguments-and-values-ht*
  (let ((ht (make-hash-table)))
    (declare (hash-table ht))
    (loop for pair in
      '((bad-lisp-objectp . (1 . 1))
        (apropos . (nil . 0))
        (aref . (nil . 1))
        (array-displacement . (1 . 2))
        (decode-float . (1 . 3))
        (expansion-alist-pkg-names-memoize . (1 . 1))
        (fchecksum-obj . (1 . 1))
        (worse-than . (2 . 1))
        (find-symbol . (nil . 2))
        (function . (nil . 1))
        (get-properties . (2 . 3))
        (gethash . (nil . 2))
        (integer-decode-float (1 . 3))
        (intern . (nil . 2))
        (lambda . (nil . 1))
        (list . (nil . 1))
        (list* . (nil . 1))
        (macroexpand . (nil . 2))
        (macroexpand-1 . (nil . 2))
        (pprint-dispatch  . (nil . 2))
        (prog1 . (nil . 1))
        (prog2 . (nil . 1))
        (quote . (1 . 1))) do
      (setf (gethash (car pair) ht)
            (cdr pair)))
    (loop for sym in
          '(car cdr caar cadr cdar cddr caaar cadar cdaar
            cddar caadr caddr cdadr cdddr caaaar cadaar cdaaar cddaar
            caadar caddar cdadar cdddar caaadr cadadr cdaadr cddadr
            caaddr cadddr cdaddr cddddr) do
            (setf (gethash sym ht) '(1 . 1)))
    ht)

  "The hash table *NUMBER-OF-ARGUMENTS-AND-VALUES-HT* maps a symbol fn
  to a cons pair (a . d), where a is the number of inputs and d is the
  number of outputs of fn.  NIL for a or d indicates 'don't know'.")

(declaim (hash-table *number-of-arguments-and-values-ht*))

(defun-one-output input-output-number-error (fn)
  ;; [Jared]: bozo this is horrible, we should provide an sane interface
  ;; to this instead of just exposing it...
  (format t "What is the number of inputs and output of ~a, please? ~%; To ~
             assert that ~a takes, say, 2 inputs and returns 1 output, do ~% ~
             (setf (gethash '~a acl2::*number-of-arguments-and-values-ht*) ~
             (cons 2 1))."
       fn fn fn)
  (error "input-output-number-error: **: ~a" fn))

(defun-one-output number-of-arguments (fn)
  ;; A NIL value returned by NUMBER-OF-ARGUMENTS means 'don't know'.
  (let* ((state *the-live-state*)
         (w (w state))
         (pair (gethash fn *number-of-arguments-and-values-ht*)))
    (cond
     ((not (symbolp fn)) nil)
     ((and (consp pair) (integerp (car pair))) (car pair))
     ((let ((formals (getprop fn 'formals t 'current-acl2-world w)))
        (and (not (eq t formals))
             (length formals))))
     ((not (fboundp fn)) nil)
     ((macro-function fn) nil)
     ((special-operator-p fn) nil)
     #+Clozure
     ((multiple-value-bind (req opt restp keys)
          (ccl::function-args (symbol-function fn))
        (and (null restp)
             (null keys)
             (integerp req)
             (eql opt 0)
             req)))
     (t nil))))

(defun-one-output number-of-return-values (fn)
  ;; A NIL value returned by NUMBER-OF-RETURN-VALUES means 'don't know'.
  (let*
    ((pair (gethash fn *number-of-arguments-and-values-ht*))
     (state *the-live-state*)
     (w (w state)))
    (cond
     ((not (symbolp fn)) nil)
     ((and (consp pair) (integerp (cdr pair))) (cdr pair))
     ((member fn '(let let* mv-let progn if return-last))
      (error "It is curious to ask about 'the' number of return values of ~a ~
              because the answer is that it depends."
           fn))
     ((not (eq t (getprop fn 'formals t 'current-acl2-world w)))
      (len (stobjs-out fn w))))))




; Timing Utilities ------------------------------------------------------------
;
; [Jared]: dealt with this in books/memoize/timer.lsp

(defg *float-ticks/second* 1.0)

(defg *float-internal-time-units-per-second*
  (float internal-time-units-per-second))

(declaim (float *float-ticks/second*
                *float-internal-time-units-per-second*))

(defabbrev internal-real-time ()
  #+(and RDTSC (not 32-bit-target)) ; faster for 64
  (the mfixnum (ccl::rdtsc))
  #+(and RDTSC 32-bit-target) ; slower for 32
  (the mfixnum (mod (ccl::rdtsc64) most-positive-mfixnum))
  #-RDTSC (the mfixnum (mod (get-internal-real-time)
                            most-positive-fixnum)))

(defun-one-output float-ticks/second-init ()
  (setq *float-ticks/second*
        #+RDTSC
        (let ((i1 (ccl::rdtsc64))
              (i2 (progn (sleep .01) (ccl::rdtsc64))))
          (if (>= i2 i1)
              (* 100 (float (- i2 i1)))
            (error "(float-ticks/second-init).")))
        #-RDTSC
        *float-internal-time-units-per-second*)
  (check-type *float-ticks/second*
              (and float (satisfies plusp))))




; SAFE-INCF ------------------------------------------------------------------
;
; [Jared]: this is horrible and is bombing out on us in some big scripts.  we
; probably would rather wrap around for performance counting than cause an
; error, or, can we maybe even just use bignums here?

(defun-one-output safe-incf-aux-error (x inc where)
  (error "~%; SAFE-INCF-AUX: ** Error: ~a."
         (list :x x :inc inc :where where)))

(defmacro safe-incf-aux (x inc where)
  (cond
   ((not (or (symbolp inc)
             (and (< inc most-positive-mfixnum)
                           (> inc 0))))
    (safe-incf-aux-error x inc where))
   ((and (true-listp x)
              (equal (len x) 3)
              (member (car x) '(aref svref))
              (symbolp (nth 1 x))
              (consp (nth 2 x)))
    (let ((idx (make-symbol "IDX")))
      `(let ((,idx (the fixnum ,(nth 2 x))))
         (declare (type fixnum ,idx))
         (safe-incf (,(nth 0 x)
                     ,(nth 1 x)
                     ,idx)
                    ,inc
                    ',where))))
   (t (let ((v (make-symbol "V")))
        `(let ((,v (the mfixnum ,x)))
           (declare (type mfixnum ,v))
           (cond ((<= ,v (the mfixnum
                                    (- most-positive-mfixnum
                                       (the mfixnum ,inc))))
                       (setf (the mfixnum ,x)
                             (the mfixnum (+ ,v (the mfixnum ,inc))))
                       nil)
                      (t (safe-incf-aux-error ',x ',inc
                                              ',where))))))))

(defmacro safe-incf (x inc &optional where)

  "SAFE-INCF is a raw Lisp macro that behaves the same as INCF when
  both X and INC are nonnegative MFIXNUMs and their sum is a
  nonnegative MFIXNUM.  In a call of (SAFE-INCF x inc), X must be a
  place that holds an MFIXNUM.  INC must evaluate to an MFIXNUM.  Both
  X and INC must evaluate without side effects, so that it is
  impossible to tell which was executed first or whether only one or
  both were executed.  If INC is not positive, no update takes place
  at all.  Otherwise, if the sum of the values of X and INC is not an
  MFIXNUM, which is tested without causing an error, a run-time error
  will be caused.  Else, if the sum is an MFIXNUM then, as with INCF,
  the place X will be set to hold the sum of the old value of that
  place and the value of INC.  The value returned by SAFE-INCF is NIL.
  Caution:  INC may be evaluated first, which is why side effects are
  prohibited.

  An optional third parameter is merely to help with error location
  identification.

  In (SAFE-INCF (AREF A (FOO)) INC), (FOO) is only evaluted once.
  Same for SVREF."

  (cond ((integerp inc)
         (if (<= inc 0)
             nil
           `(safe-incf-aux ,x ,inc ,where)))
        ((symbolp inc)
         `(if (>= 0 (the mfixnum ,inc))
                   nil
                   (safe-incf-aux ,x ,inc ,where)))
        (t (let ((incv (make-symbol "INCV")))
             `(let ((,incv (the mfixnum ,inc)))
                (declare (type mfixnum ,incv))
                (if (>= 0 ,incv)
                         nil
                         (safe-incf-aux ,x ,incv ,where)))))))





; PONSING ---------------------------------------------------------------------
;
; [Jared]: dealt with this in books/memoize/pons.lsp

(defparameter *count-pons-calls* t
  "If *COUNT-PONS-CALLS*, then each call of PONS increments
  *PONS-CALL-COUNTER* by 1, and each call of PONS that does not find
  the desired PONS to already exist increments *PONS-MISSES-COUNTER*
  by 1.")

(defg *pons-call-counter* 0)
(defg *pons-misses-counter* 0)
(declaim (type mfixnum *pons-call-counter*))
(declaim (type mfixnum *pons-misses-counter*))

(defmacro maybe-count-pons-calls ()
  (and *count-pons-calls*
       '(safe-incf *pons-call-counter* 1 maybe-count-pons-calls)))

(defmacro maybe-count-pons-misses ()
  (and *count-pons-calls*
       '(safe-incf *pons-misses-counter* 1 maybe-count-pons-misses)))

(defun-one-output assoc-no-error-at-end (x l)
  ;; We assume that every element of L is CONSP.
  (if (typep x '(or cons symbol (and array string)))
      (loop (if (consp l)
                (let ((al (car l)))
                  (if (eq x (car al))
                      (return al)
                    (setq l (cdr l))))
              (return nil)))
    (loop (if (consp l)
              (let ((al (car l)))
                (if (eql x (car al))
                    (return al)
                  (setq l (cdr l))))
            (return nil)))))

(defun-one-output too-long (x n)
  (declare (type fixnum n))
  ;; (TOO-LONG x n) == (> (LENGTH x) n) provided x a noncircular list and
  ;; n is a nonnegative fixnum.  TOO-LONG is perhaps faster than LENGTH
  ;; because (a) LENGTH has to worry about its argument being a circular
  ;; list, (b) LENGTH may worry about the answer exceeding
  ;; MOST-POSITIVE-FIXNUM, and (c) LENGTH must consider the possibility
  ;; that its argument is a vector.
  (loop (cond ((atom x) (return nil))
              ((eql n 0) (return t))
              (t (setq x (cdr x))
                 (setq n (the fixnum (1- n)))))))

(defconstant atom-case-fudge (+ 129 (expt 2 25)))
(defconstant most-positive-fudge (1- (expt 2 24)))
(defconstant most-negative-fudge (- (expt 2 24)))
(defconstant -most-negative-fudge (- most-negative-fudge))

#+Clozure
(defun-one-output atom-case (s)
  (cond
   ((symbolp s)
    (cond ((eq s nil) 0)
          ((eq s t) 1)
          (t (let ((v (get (the symbol s) 'hons-hash-key)))
               (cond ((null v)
                      (let ((c (ccl::static-cons s nil)))
                        (setq v (+ atom-case-fudge
                                   (the fixnum (ccl::%staticp c))))
                        (setf (get (the symbol s) 'hons-hash-key) c)
                        (rplacd (the cons c) v)
                        v))
                     (t (cdr (the cons v))))))))
   ((and (typep s 'fixnum)
         (> (the fixnum s) most-negative-fudge)
         (<= (the fixnum s) most-positive-fudge))
    (the fixnum (+ -most-negative-fudge (the fixnum s))))))

(defmacro sqmpf ()
  (isqrt most-positive-fixnum))

(defmacro hmnf ()

; Half MOST-NEGATIVE-FIXNUM.

  (ceiling (/ most-negative-fixnum 2)))

(defmacro static-hons-shift ()
  (ceiling (/ (integer-length most-positive-fixnum) 2)))

#+Clozure
(defun-one-output addr-for (x y)
  (let ((idx (let ((n (ccl::%staticp x)))
               (cond (n (+ atom-case-fudge (the fixnum n)))
                     (t (atom-case x)))))
        (large-case nil))
    (cond (idx (cond ((and (typep idx 'fixnum)
                           (< (the fixnum idx) (sqmpf)) nil))
                     (t (setq large-case t))))
          (t (return-from addr-for nil)))
    (let ((idy (let ((n (ccl::%staticp y)))
                 (cond (n (+ atom-case-fudge (the fixnum n)))
                       (t (atom-case y))))))
      (cond (idy (cond ((and (typep idy 'fixnum)
                             (< (the fixnum idy) (sqmpf))) nil)
                       (t (setq large-case t))))
            (t (return-from addr-for nil)))

; ADDR-FOR is 1-1, in a sense, for a two argument function, when not
; NIL.  That is, for all ACL2 objects x1, x2, y1, and y1, if (addr-for
; x1 y1) is not NIL and is equal to (addr-for x2 y2), then x1 is equal
; to x2 and y1 is equal to y2.

; Here is a sketch of a proof that if mpf = 2^60-1 and mnf = -2^60,
; then the ranges of large-case and the non-large case of ADDR-FOR do
; not intersect.  In the large case, one of idx or idy, must be >=
; 2^30, so (+ (/ (* (idx+idy+1) (idx+idy)) 2) idy) > 2^59.  Adding in
; -2^59 means that the large result will be positive. In the non-large
; case, the result of the logior will be <= 2^60-1, so the result of
; adding -2^60 will make the non-large result negative.

      (cond (large-case
             (let* ((z (+ idx idy))
                    (z1 (+ 1 z)))
               (if (oddp z)
                   (setq z1 (ash z1 -1))
                 (setq z (ash z -1)))
               (+ idy (+ (hmnf) (* z z1)))))
            (t (+ (the fixnum
                    (logior
                     (the fixnum
                       (ash (the fixnum idx) (static-hons-shift)))
                     (the fixnum idy)))
                  most-negative-fixnum))))))



; This code has the 'feature' that if the condition causes an error,
; so will the memoized function.

; PONS differs from HONS in that it does not honsify its arguments and
; in that it takes a hash table as a third argument.  We use PONS in
; memoization.

; We use PONS instead of HONS in memoization because we could not
; afford to honsify (using hons-shrink-alist!) certain alists in
; certain biology tests.  About the same time, we (gratuitously)
; decided to stop hons'ifying the output of memoized functions.


(defun-one-output pons (x y ht)
  (declare (hash-table ht))

; A crucial fact is:
; (implies (equal (pons x y ht) (pons x' y' ht))
;          (and (equal x x')
;               (equal y y'))

; Ignore the ht for the moment.  Suppose that
;    (equal (pons x (pons y z)) (pons x' (pons y' z'))).
;
; It follows then that x=x', y=y', and z=z'.

  (let ((xval nil)
        (yval nil)
        (ans nil))

; We have taken string normalization out of pons because there might
; be a chance of confusing a 'normal' string with a stobj.

; If x1, ..., xn is pointwise EQL to y1, ..., yn, then are we sure
; that (pist* x1 ... xn) is EQ to (pist* y1 ... yn)?

; If CONS exists, then return it.  Does CDR exist in hash table?

    #+Clozure
    (let ((addr (addr-for x y)))
      (when addr (return-from pons addr)))

    (maybe-count-pons-calls)
    (setq yval (gethash y (the hash-table ht)))

; Does CAR exist in hash table?

    (cond (yval
           (cond ((not (consp yval))
                  (setq xval (gethash x (the hash-table yval)))
                  (cond (xval (setq ans xval))))
                 ((setq ans (assoc-no-error-at-end x yval))))))
    (cond

; If PONS found, then return previous CONS from hash table.
     (ans)

; Otherwise, maybe create new CONS and install in hash table.

     (t
      (setq yval (gethash y ht))
      (cond
       ((null yval)
        (setq ans (cons x y))
        (setf (gethash y ht) (list ans))
        ans)
       ((consp yval)
        (let ((ans (assoc-no-error-at-end x yval)))
            (cond
             (ans)
             (t (let ((ans (cons (cons x y) yval)))
                  (maybe-count-pons-misses)
                  (cond
                   ;; Gary Byers recalls Lisp folklore that alists are faster
                   ;; than hash tables up to length 18.
                   ((too-long ans 18)
                    (let ((tab (hl-mht)))
                      (declare (hash-table tab))
                      (loop for pair in ans do
                            (setf (gethash (car pair) tab) pair))
                      (setf (gethash y ht) tab)
                      (car ans)))
                   (t (setf (gethash y ht) ans)
                      (car ans))))))))
       (t (setq xval (gethash x (the hash-table yval)))
          (cond ((not xval)
                 (maybe-count-pons-misses)
                 (setf (gethash x (the hash-table yval))
                       (setq ans (cons x y))))
                (t (setq ans xval)))
          ans))))))

(defmacro pist* (table &rest x)
  (cond ((atom x) x)
        ((atom (cdr x)) (car x))
        (t (list 'pons (car x)
                 (cons 'pist* (cons table (cdr x))) table))))



; Identifying functions that are safe to memoize --------------------------
;
; [Jared]: This is really gross and I don't think it's the right way to do it
; at all.  We need to figure out something better.  Maybe we should instead use
; some kind of marking scheme on the symbol to say never memoize this function.
; (Modified by Matt K. 8/26/13 to avoid a weird error in profile-all after
; (include-book "memoize/old/profile" :dir  :system).)

(defvar *never-memoize-ht*
  (let ((ht (make-hash-table :test 'eq)))
    (loop for x in
          '(bytes-used
            memoize-summary
            memoize-summary-after-compute-calls-and-times
            #+rdtsc ccl::rdtsc
            *
            +
            -
            <
            <=
            =
            >
            >=
            abort
            adjoin
            adjust-array
            allocate-instance
            append
            apply
            apropos
            apropos-list
            aref
            arrayp
            assoc
            assoc-if
            assoc-if-not
            atan
            atom
            bit
            bit-and
            bit-andc1
            bit-andc2
            bit-eqv
            bit-ior
            bit-nand
            bit-nor
            bit-not
            bit-orc1
            bit-orc2
            bit-xor
            break
            butlast
            car
            cdr
            ceiling
            cerror
            change-class
            char-equal
            char-greaterp
            char-lessp
            char-not-equal
            char-not-greaterp
            char-not-lessp
            char/=
            char<
            char<=
            char=
            char>
            char>=
            clear-input
            clear-memoize-tables
            clear-output
            compile
            compile-file
            compile-file-pathname
            compiler-macro-function
            complex
            compute-restarts
            concatenate
            continue
            copy-pprint-dispatch
            copy-readtable
            copy-symbol
            count
            count-if
            count-if-not
            decode-universal-time
            delete
            delete-duplicates
            delete-if
            delete-if-not
            describe
            digit-char
            digit-char-p
            directory
            dribble
            ed
            encode-universal-time
            enough-namestring
            ensure-directories-exist
            ensure-generic-function
            eq
            eql
            error
            eval
            every
            export
            fboundp
            fceiling
            ffloor
            file-position
            fill
            find
            find-class
            find-if
            find-if-not
            find-method
            find-restart
            find-symbol
            finish-output
            fixnum-to-symbol
            float
            float-sign
            floor
            force-output
            format
            fresh-line
            fround
            ftruncate
            funcall
            gensym
            gentemp
            get
            get-dispatch-macro-character
            get-internal-real-time
            get-internal-run-time
            get-macro-character
            get-properties
            get-setf-expansion
            getf
            gethash
            if
            import
            initialize-instance
            intern
            internal-real-time
            intersection
            invalid-method-error
            invoke-restart
            last
            ld-fn
            len
            len1
            length
            lisp-implementation-type
            list
            list*
            listen
            load
            log
            macro-function
            macroexpand
            macroexpand-1
            make-array
            make-broadcast-stream
            make-concatenated-stream
            make-condition
            make-dispatch-macro-character
            make-hash-table
            make-instance
            make-list
            make-load-form
            make-load-form-saving-slots
            make-package
            make-pathname
            make-random-state
            make-sequence
            make-string
            make-string-input-stream
            make-string-output-stream
            map
            map-into
            mapc
            mapcan
            mapcar
            mapcon
            mapl
            maplist
            max
            member
            member-if
            member-if-not
            memoize-call-array-grow
            memoize-eval-compile
            memoize-fn
            merge
            merge-pathnames
            method-combination-error
            mf-1st-warnings
            mf-2nd-warnings
            mf-warnings
            mismatch
            muffle-warning
            nbutlast
            nconc
            nintersection
            no-applicable-method
            no-next-method
            not
            notany
            notevery
            nset-difference
            nset-exclusive-or
            nstring-capitalize
            nstring-downcase
            nstring-upcase
            nsublis
            nsubst
            nsubst-if
            nsubst-if-not
            nsubstitute
            nsubstitute-if
            nsubstitute-if-not
            null
            nunion
            open
            pairlis
            parse-integer
            parse-namestring
            pathname-device
            pathname-directory
            pathname-host
            pathname-name
            pathname-type
            peek-char
            position
            position-if
            position-if-not
            pprint
            pprint-dispatch
            pprint-fill
            pprint-indent
            pprint-linear
            pprint-newline
            pprint-tab
            pprint-tabular
            prin1
            princ
            princ-to-string
            print
            print-object
            profile-fn
            profile-acl2
            profile-all
            random
            rassoc
            rassoc-if
            rassoc-if-not
            read
            read-byte
            read-char
            read-char-no-hang
            read-delimited-list
            read-from-string
            read-line
            read-preserving-whitespace
            read-sequence
            reduce
            reinitialize-instance
            remove
            remove-duplicates
            remove-if
            remove-if-not
            rename-file
            rename-package
            replace
            require
            reverse-strip-cars
            reverse-strip-cdrs
            room
            round
            sbit
            search
            set-difference
            set-dispatch-macro-character
            set-exclusive-or
            set-macro-character
            set-pprint-dispatch
            set-syntax-from-char
            shadow
            shadowing-import
            shared-initialize
            signal
            signum
            slot-missing
            some
            sort
            stable-sort
            store-value
            string-capitalize
            string-downcase
            string-equal
            string-greaterp
            string-lessp
            string-not-equal
            string-not-greaterp
            string-not-lessp
            string-upcase
            string/=
            string<
            string<=
            string=
            string>
            string>=
            stringp
            sublis
            subseq
            subsetp
            subst
            subst-if
            subst-if-not
            substitute
            substitute-if
            substitute-if-not
            subtypep
            svref
            symbol-to-fixnum
            symbol-to-fixnum-create
            symbolp
            sync-memoize-call-array
            terpri
            translate-logical-pathname
            translate-pathname
            tree-equal
            true-listp
            truncate
            typep
            unexport
            unintern
            union
            unread-char
            unuse-package
            update-instance-for-different-class
            update-instance-for-redefined-class
            upgraded-array-element-type
            upgraded-complex-part-type
            use-package
            use-value
            user-homedir-pathname
            values
            vector-push-extend
            warn
            wild-pathname-p
            write
            write-byte
            write-char
            write-line
            write-sequence
            write-string
            write-to-string
            y-or-n-p
            yes-or-no-p)
          do (setf (gethash x ht) t))
    ht))

(defun never-memoize-fn (fn)
  (setf (gethash fn *never-memoize-ht*) t))

(defun never-memoize-p (fn)
  (if (gethash fn *never-memoize-ht*)
      t
    nil))


; The following was inserted by Jared to keep his place; stuff above is "done"
; and stuff below is "todo".

; -------------------------------------------------------------------------
; -------------------------------------------------------------------------
;                         ZZ THE GREPPABLE LINE ZZ
; -------------------------------------------------------------------------
; -------------------------------------------------------------------------


;  recording vars

; To minimize metering overhead costs, one may set these "*RECORD-"
; variables to NIL before memoizing.

; *RECORD-BYTES* and other *RECORD-...* variables are bound in
; REMEMOIZE-ALL, so we use DEFPARAMETER rather than DEFG.

(defparameter *record-bytes*
  ;; BOZO why not do this in all ccls...?
  (and (member :Clozure *features*)
       (> most-positive-fixnum (expt 2 32)))
  "In 64-bit Clozure Common Lisp, if *RECORD-BYTES* is not NIL when a
  function is memoized, we keep track of heap bytes allocated during
  calls of that function.")

(defparameter *record-calls* t
  "If *RECORD-CALLS* when a function is memoized,
  we count all calls of the function.")

(defparameter *record-hits* t
  "If *RECORD-HITS* is not NIL when a function is memoized, we count
  the number of times that a previously computed answer is used
  again.")

(defparameter *record-hons-calls* t
  "If *RECORD-HONS-CALLS* in not NIL a function is memoized, HONS
  calls are counted.")

(defparameter *record-mht-calls* t
  "If *RECORD-HONS-CALLS* is not NIL at the time a function is
  memoized, we record the number of times that a memo hash-table for
  the function was is counted.")

(defparameter *record-pons-calls* t
  "If *RECORD-PONS-CALLS* is not NIL at the time a function is
  memoized, pons calls are counted.")

(defparameter *record-time* t
  "If *RECORD-TIME* is not NIL the time a function is memoized, we
  record the elapsed time for each outermost call of the function.")


;  reporting vars

(defv *report-bytes* #+Clozure t #-Clozure nil
  "If *REPORT-BYTES* is not NIL, then MEMOIZE-SUMMARY prints the
  number of bytes allocated on the heap.")

(defv *report-calls* t
  "If *REPORT-CALLS* is not NIL, MEMOIZE-SUMMARY prints the number of
  calls.")

(defv *report-calls-from* t
  "If *REPORT-CALLS-FROM* is not NIL, MEMOIZE-SUMMARY prints which
functions called a function, how many times, and how long the calls
took.")

(defv *report-calls-to* t
  "If *REPORT-CALLS-TO* is not NIL, MEMOIZE-SUMMARY prints which
functions were called by given function, how many times, and how long
the calls took.")

(defv *report-hits* t
  "If *REPORT-HITS* is not NIL, MEMOIZE-SUMMARY prints the number of
  times that a previously computed answer was reused.")

(defv *report-hons-calls* t
  "If *REPORT-HONS-CALLS* is not NIL, then MEMOIZE-SUMMARY prints the
  number of times that hons was called.")

(defv *report-mht-calls* t
  "If *REPORT-MHT-CALLS* is not NIL, then MEMOIZE-SUMMARY prints the
  number of times that a memo hash-table for the function was created.
  This may be of interest to those who memoize functions that deal in
  changing stobjs; the memoization machinery sometimes 'forgets' an
  entire memoization hash table out of an abundance of caution, and
  then may later need to create it afresh.")

(defv *report-pons-calls* t
  "If *REPORT-PONS-CALLS* is not NIL, MEMOIZE-SUMMARY prints the
  number of calls of PONS.")

(defv *report-time* t
  "If *REPORT-TIME* is not NIL, MEMOIZE-SUMMARY prints the total time
  used to compute the outermost calls.")

(defv *report-on-memo-tables* t
  "If *REPORT-ON-MEMO-TABLES* is not NIL, MEMOIZE-SUMMARY prints
  information about memo tables.")

(defv *report-on-pons-tables* t
  "If *REPORT-ON-PONS-TABLES* is not NIL, MEMOIZE-SUMMARY prints
  information about pons tables.")

(defg *memoize-info-ht*
  ;; This has two mappings in one:
  ;;
  ;;   1. It maps each currently memoized function symbol, fn, to a
  ;;      DEFREC record of type MEMO-INFO-HT-ENTRY.
  ;;
  ;;   2. It maps each NUM back to the corresponding symbol.
  (hl-mht))

(declaim (hash-table *memoize-info-ht*))

(defrec memoize-info-ht-entry
  ;; vaguely ordered by most frequently referenced first
  (ext-anc-attachments ;; see the Essay on Memoization with Attachments

   ;; start-time is a symbol whose val is the start time of the current,
   ;; outermost call of fn, or -1 if no call of fn is in progress.
   start-time

   num              ;; an integer, unique to fn.  (for stats?)
   tablename        ;; a symbol whose value is the memoize table for fn.
   ponstablename    ;; a symbol whose value is the pons table for fn
   condition        ;; T or NIL. :condition arg as passed to memoize-fn
   inline           ;; T or NIL. :inline arg as passed to memoize-fn
   memoized-fn      ;; the new value of (symbol-function fn)
   old-fn           ;; the old value of (symbol-function fn), or nil.
   fn               ;; a symbol, the name of the function being memoized
   sts              ;; the stobj memotable lists for fn
   trace            ;; T or NIL. :trace arg as passed to memoize-fn
   before           ;; form to evaluate first

   ;; the function body actually used, in the inline=t
   ;; case, as supplied (or as computed, if not supplied)
   cl-defun

   formals           ;; as supplied (or as computed, if not supplied)
   commutative       ;; asserts this is a binary commutative function
   specials          ;; horrible hack for raw functions that read *specials*
   stobjs-in         ;; as supplied (or as computed, if not supplied)
   stobjs-out        ;; as supplied (or as computed, if not supplied)

   record-bytes      ;; value as bound at the time MEMOIZE-FN is called
   record-calls      ;;        ''
   record-hits       ;;        ''
   record-hons-calls ;;        ''
   record-mht-calls  ;;        ''
   record-pons-calls ;;        ''
   record-time       ;;        ''

   forget               ;; Boolean, clears memo when outermost call exits.
   memo-table-init-size ;; integer, default *mht-default-size*
   )
  t)


(defg *memoize-call-array*
  (make-array 1 :element-type 'mfixnum :initial-element 0)

  "*MEMOIZE-CALL-ARRAY*, 'ma' for short, is used for storage of the
  monitoring information for memoized functions.  ma has as its length
  4 times the square of the maximum number of memoized functions.

  ma is initialized in MEMOIZE-INIT.  Think of ma as a two dimensional
  array with dimensions (twice the max number of memoized functions) x
  (twice the max number of memoized functions).  Each 'column'
  corresponds to info about a memoized function, but the first five
  columns are 'special'.  We count rows and columns starting at 0.
  Column 0 is used as scratch space by COMPUTE-CALLS-AND-TIMES for
  sums across all functions.  Columns 1, 2, and 3 are not currently
  used at all.  Column 4 is for the anonymous 'outside caller'.
  Column 5 is for the first memoized function.  In columns 5 and
  greater, row 0 is used to count 'bytes', 1 'hits', 2 MHT calls, 3
  HONS calls, and 4 PONS calls.

  The elements of an ma column starting at row 10 are for counting and
  timing info.  Suppose column 7 corresponds to the memoized function
  FOO and column 12 corresponds to the memoized function BAR.
  Whenever FOO calls BAR, element 2*12 of column 7 will be incremented
  by 1, and the total elapsed time for the call will be added to
  element 2*12+1 of column 7.

  Though ma may 'grow', it may not grow while any memoized function is
  running, and here is why: every memoized function has a cached
  opinion about the size of ma.  To avoid an abort during a call of
  MEMOIZE one may call (MEMOIZE-HERE-COME n) to assure that ma has
  room for at least n more memoized functions.")

(defg *compute-array* (make-array 0)

  "*COMPUTE-ARRAY*, ca for short, is an array of proper lists.  At the
  end of a call of COMPUTE-CALLS-AND-TIMES, which is called by
  MEMOIZE-SUMMARY, (aref ca n) will contain the numbers of the
  functions that have called the function numbered n.")

(declaim (type (simple-array t (*)) *compute-array*))

(eval-when
 #-cltl2
 (load eval)
 #+cltl2
 (:load-toplevel :execute)
 (proclaim `(type (simple-array mfixnum
                                (*)) *memoize-call-array*)))

(defv *initial-max-memoize-fns* 500)

(defg *2max-memoize-fns* (* 2 *initial-max-memoize-fns*))

(defconstant *ma-bytes-index*       0)
(defconstant *ma-hits-index*        1)
(defconstant *ma-mht-index*         2)
(defconstant *ma-hons-index*        3)
(defconstant *ma-pons-index*        4)

(defconstant *ma-initial-max-symbol-to-fixnum* 4)

(defg *max-symbol-to-fixnum* *ma-initial-max-symbol-to-fixnum*)

(declaim (type fixnum
               *max-symbol-to-fixnum*
               *initial-2max-memoize-fns*
               *ma-initial-max-symbol-to-fixnum*
               *2max-memoize-fns*))

(defg *caller* (* *ma-initial-max-symbol-to-fixnum* *2max-memoize-fns*)
  "When memoized functions are executing in parallel, the value of
  *CALLER* and of statistics derived therefrom may be meaningless and
  random.")

(declaim (type fixnum *caller*))

(defn memoize-here-come (n)
  (let ((m (ceiling
            (+ 100 (* 1.1 (- n (- (/ *2max-memoize-fns* 2)
                                  (floor
                                   (/ (hash-table-count
                                       *memoize-info-ht*)
                                      2)))))))))
    (when (posp m) (memoize-call-array-grow (* 2 m)))))






; Essay on Memoization Involving Stobjs

; We allow memoization of functions that take user-defined stobjs (not state)
; as arguments but do not return stobjs.  The key is the use of memoize-flush
; to "forget" all that was remembered for certain functions that use certain
; stobjs.  We must keep memoize-flush very fast in execution so as not to slow
; down stobj update or resize operations in general.  Indeed, memoize-flush may
; (according to tests run) incur essentially no cost (after Version_4.3) as
; long as no functions with stobj arguments are actually memoized.

; The following example shows why we disallow memoization of functions that
; return stobjs.  First, redefine memoize-table-chk by eliminating the branch
; that causes an error in the presence of stobj names in stobjs-out.  Then
; start up ACL2 and submit the forms below.  The problem is that we do not
; inhibit storing a result in the case that the stobj has changed from the time
; the function was called to the time the result is to be stored.

; (defstobj st fld)
; (defun foo (st)
;   (declare (xargs :stobjs st))
;   (let ((st (update-fld (cons (fld st) (fld st)) st)))
;     (mv (fld st) st)))
; (foo st) ; updates (fld st), returns (mv (nil) st)
; (memoize 'foo)
; (foo st) ; updates (fld st), returns (mv ((nil) nil) st)
; (foo st) ; no longer updates (fld st)
; (foo st) ; no longer updates (fld st)
; (fld st) ; still ((nil . nil). (nil . nil))

(defun memoize-flush1 (lst)

; Experiments showed that when lst is nil, it is faster to call this function
; then to inline its code into the body of memoize-flush.

; We "forget" all memoized values by clearing all necessary memoize tables; see
; the comment about memoize-flush in memoize-fn.  We leave the pons table alone
; in order to keep this flushing operation as fast as possible.  Note that the
; pons table merely stores keys to be looked up in the memo table, so there is
; no soundness issue, and in fact those pons table entries might remain useful;
; the cost is the space taken up by the pons tables.

  (loop for sym in lst do
        (when (boundp (the symbol sym)) ; Is this test needed?
          (let ((old (symbol-value (the symbol sym))))
            (unless (or (null old) (empty-ht-p old))
              (setf (symbol-value (the symbol sym)) nil))))))

(defmacro memoize-flush (st)

; See memoize-flush1 for a relevant discussion.

  (and st
       (let ((s (st-lst st)))
         `(when ,s ; optimization
            (memoize-flush1 ,s)))))

(defparameter *memo-max-sizes*
  ;; Binds function names to memo-max-sizes-entry structures.
  ;;
  ;; Jared originally added this table because he wanted to know how big
  ;; memoization tables were getting (so that he could set up appropriate
  ;; initial sizes), but when tables are cleared they are thrown away, so for
  ;; tables that are frequently cleared it wasn't possible to see how large the
  ;; table had become.
  ;;
  ;; After seeing the information, we thought it might be a good idea to use it
  ;; to infer what a good table size might be when we recreate the memo table.
  ;; See the function predict-good-memoize-table-size for details.
  (make-hash-table))

; BOZO should we use this information to try to guess better sizes and
; rehash thresholds for memoize tables?

(defrec memo-max-sizes-entry
  ;; A single entry in the *memo-table-max-sizes* table.
  (num-clears   ; how many times has this table been cleared (nat)
   max-pt-size  ; maximum size of the pons table before any clear (nat)
   max-mt-size  ; maximum size of the memo table before any clear (nat)
   avg-pt-size  ; average size of pons table before any clear (float)
   avg-mt-size  ; average size of memo table before any clear (float)
   )
  t)

(defun make-initial-memoize-hash-table (fn init-size)

; FN is the name of a function.  INIT-SIZE is the initial size that the user
; says we should use.  We want to come create and return a new hash table for
; this function's memoization table.  One possible implementation of this
; function would just be:
;
;    (hl-mht :size init-size)
;
; But we hope to do better.  Our idea is to look at how large the table has
; been in the past, and use that size to make a good prediction of how large
; the table will be this time.
;
; The idea here is to build a table that's just slightly bigger than the
; average size we've seen so far.  We arbitrarily say that "slightly bigger"
; means 1.2x the previous average.
;
; By itself this would be scary.  Big hash tables can use a lot of memory: a
; rule of thumb in CCL is that 1 MB of space buys you 44,000 entries.  I want
; to avoid creating a hundred-megabyte memo tables for a function just because
; it was used heavily for a short while and then cleared once before.  On the
; other hand, if a memo table truly does get large on a regular basis, then we
; do want to guess a big size for it.
;
; So in this code, I enforce an artificial maximum on our guess, but I allow
; this maximum to grow with the number of times we've cleared the table.
; Basically I allow the maximum guess to grow at a rate of 1 MB per clear.  If
; a table has been cleared 100 times, I think we have a pretty good sense of
; its average usage and we can be comfortable allocating up to 100 MB for it.
; If it's been cleared more than 1000 times, the cap is a gigabyte.  But of
; course, to actually reach such a large guess, you'd have to be repeatedly
; filling up the table to contain millions of entries and then clearing it.

  (let* ((max-sizes
          ;; The previously recorded sizes of this table, if any exist.
          (gethash fn *memo-max-sizes*))
         (size-to-use
          (if (not max-sizes)
              ;; We never cleared this memoize table before, so we don't have
              ;; anything to go on besides what the user says.  Do what they
              ;; say.
              init-size
            (let* ((nclears       (access memo-max-sizes-entry max-sizes :num-clears))
                   (avg-mt-size   (access memo-max-sizes-entry max-sizes :avg-mt-size))
                   (our-guess     (ceiling (* 1.20 avg-mt-size)))
                   (capped-guess  (min our-guess (* nclears 44000)))
                   (final-guess   (max 60 init-size capped-guess)))
              final-guess))))
    ;; BOZO also try to guess a better rehash-size?
    (hl-mht :size size-to-use)))

(defun make-initial-memoize-pons-table (fn init-size)
  (declare (ignorable init-size))

; This is similar to make-initial-memoize-table, but for the pons table.

  (let* ((max-sizes (gethash fn *memo-max-sizes*))
         (size-to-use
          (if (not max-sizes)
              ;; We've never cleared this pons table before, so we don't have
              ;; anything to go on besides what the user says.  Now, this is
              ;; subtle.  Originally I just returned init-size here, i.e., "do
              ;; what the user says."  But while this makes sense for the memo
              ;; table, it doesn't necessarily make much sense for the pons
              ;; table.  In particular, we can sometimes avoid ponsing by using
              ;; our static-cons-index-hashing scheme.
              ;;
              ;; In some sense it would probably be good to give the user
              ;; explicit control over the pons table size.  But for now, the
              ;; main use of our memoize table size controls is to set things
              ;; up for big BDD/AIG/SEXPR operations where we've got honsed
              ;; data.  So, I'm going to just use 60 here, and say that the
              ;; memo-table-init-size only affects the memoize table and not
              ;; the pons table.
              60
            (let* ((nclears       (access memo-max-sizes-entry max-sizes :num-clears))
                   (avg-pt-size   (access memo-max-sizes-entry max-sizes :avg-pt-size))
                   (our-guess     (ceiling (* 1.20 avg-pt-size)))
                   (capped-guess  (min our-guess (* nclears 44000)))
                   (final-guess   (max 60 init-size capped-guess)))
              final-guess))))
    ;; BOZO also try to guess a better rehash-size?
    (hl-mht :size size-to-use)))

(defun update-memo-max-sizes (fn pt-size mt-size)
  ;; Called during clear-one-memo-and-pons-hash when the tables existed.
  ;; When called, pt-size and mt-size are nonzero.
  (let ((old (gethash fn *memo-max-sizes*)))
    (if (not old)
        (setf (gethash fn *memo-max-sizes*)
              (make memo-max-sizes-entry
                    :num-clears 1
                    :max-pt-size pt-size
                    :max-mt-size mt-size
                    :avg-pt-size (coerce pt-size 'float)
                    :avg-mt-size (coerce mt-size 'float)))
      (let* ((old.num-clears  (access memo-max-sizes-entry old :num-clears))
             (old.max-pt-size (access memo-max-sizes-entry old :max-pt-size))
             (old.max-mt-size (access memo-max-sizes-entry old :max-mt-size))
             (old.avg-pt-size (access memo-max-sizes-entry old :avg-pt-size))
             (old.avg-mt-size (access memo-max-sizes-entry old :avg-mt-size))
             (new.num-clears  (+ 1 old.num-clears)))
        (setf (gethash fn *memo-max-sizes*)
              (make memo-max-sizes-entry
                    :num-clears  new.num-clears
                    :max-pt-size (max pt-size old.max-pt-size)
                    :max-mt-size (max mt-size old.max-mt-size)
                    :avg-pt-size (/ (+ pt-size (* old.avg-pt-size old.num-clears))
                                    new.num-clears)
                    :avg-mt-size (/ (+ mt-size (* old.avg-mt-size old.num-clears))
                                    new.num-clears))))))
  nil)

(defun print-memo-max-sizes ()
  (when (equal (hash-table-count *memo-max-sizes*) 0)
    (return-from print-memo-max-sizes nil))
  (format t "Memo table statistics gathered at each from when they were cleared:~%~%")
  (let ((indent 8) ;; length of "Function"
        (indent-str nil))
    (maphash (lambda (fn entry)
               (declare (ignore entry))
               (setq indent (max indent (length (symbol-name fn)))))
             *memo-max-sizes*)
    (setq indent-str (format nil "~a" (+ 2 indent)))
    (format t (concatenate 'string "~" indent-str ":@a") "Function")
    (format t " ~10:@a | ~15:@a ~15:@a | ~15:@a ~15:@a~%"
            "Clears" "PT Max" "PT Avg" "MT Max" "MT Avg")
    (maphash
     (lambda (fn entry)
       (let* ((num-clears  (access memo-max-sizes-entry entry :num-clears))
              (max-pt-size (access memo-max-sizes-entry entry :max-pt-size))
              (max-mt-size (access memo-max-sizes-entry entry :max-mt-size))
              (avg-pt-size (access memo-max-sizes-entry entry :avg-pt-size))
              (avg-mt-size (access memo-max-sizes-entry entry :avg-mt-size)))
         (format t (concatenate 'string "~" indent-str ":@a ~10:D | ~15:D ~15:D | ~15:D ~15:D~%")
                 fn num-clears
                 max-pt-size (floor avg-pt-size)
                 max-mt-size (floor avg-mt-size))))
     *memo-max-sizes*)
    (format t "~%"))
  nil)

; MEMOIZE FUNCTIONS

#+Clozure
(defmacro heap-bytes-allocated ()
  '(the mfixnum (ccl::%heap-bytes-allocated)))

(defn sync-memoize-call-array ()

  ; To be called only by MEMOIZE-INIT, MEMOIZE-CALL-ARRAY-GROW, or
  ; SAVE-MEMOIZE-CALL-ARRAY.

  (let ((n1 (the fixnum
              (* *2max-memoize-fns* *2max-memoize-fns*)))
        (n2 (1+ *max-symbol-to-fixnum*)))
    (declare (type fixnum n1 n2))
    (unless (eql n1 (length *memoize-call-array*))
      (unless (eql 1 (length *memoize-call-array*))
        (setq *memoize-call-array*
              (make-array 1 :element-type 'mfixnum
                          :initial-element 0))
        (gc$))
      (setq *memoize-call-array*
            (make-array n1
                        :element-type 'mfixnum
                        :initial-element 0)))
    (unless (eql n2 (length *compute-array*))
      (setq *compute-array*
            (make-array n2 :initial-element nil)))
    (setq *caller* (* *ma-initial-max-symbol-to-fixnum*
                      *2max-memoize-fns*))))

(defun memoize-call-array-grow
  (&optional (2nmax (* 2 (ceiling (* 3/2 (/ *2max-memoize-fns* 2))))))
  (unless (integerp 2nmax)
    (error "(memoize-call-array-grow ~s).  Arg must be an integer."
           2nmax))
  (unless (evenp 2nmax)
    (error "(memoize-call-array-grow ~s).  Arg must be even." 2nmax))
  (unless (> 2nmax 100)
    (error "(memoize-call-array-grow ~s).  Arg must be > 100." 2nmax))
  (when (<= 2nmax *2max-memoize-fns*)
    (cw "; memoize-call-array-grow: *memoize-call-array* already big enough.~%")
    (return-from memoize-call-array-grow))
  (unless (<= (* 2nmax 2nmax) most-positive-fixnum)
    (error "memoize-call-array-grow:  most-positive-fixnum exceeded.  Too ~
            many memoized functions."))
  (unless (< (* 2nmax 2nmax) array-total-size-limit)
    (error "memoize-call-array-grow: ARRAY-TOTAL-SIZE-LIMIT exceeded.  Too ~
            many memoized functions."))
  (unless (eql *caller* (* *ma-initial-max-symbol-to-fixnum*
                           *2max-memoize-fns*))
    (cw "; MEMOIZE-CALL-ARRAY-GROW was called while a memoized function~%~
         ; was executing, so call reports may be quite inaccurate.~%"))
  (setq *memoize-call-array*
        (make-array 1 :element-type 'mfixnum :initial-element 0))
  (setq *2max-memoize-fns* 2nmax)
  (sync-memoize-call-array)
  (rememoize-all)
  nil)

(defun-one-output symbol-to-fixnum-create (s)
  (check-type s symbol)
  (let ((g (gethash s *memoize-info-ht*)))
    (if g (access memoize-info-ht-entry g :num)
      (let (new)
        (loop for i fixnum from
              (if (eql *caller*
                       (* *ma-initial-max-symbol-to-fixnum*
                          *2max-memoize-fns*))
                  (1+ *ma-initial-max-symbol-to-fixnum*)
                (1+ *max-symbol-to-fixnum*))
              below (the fixnum (floor *2max-memoize-fns* 2))
              do (unless (gethash i *memoize-info-ht*)
                   (setq new i)
                   (return)))
        (cond (new
               (setq *max-symbol-to-fixnum*
                     (max *max-symbol-to-fixnum* new))
               new)
              (t (memoize-call-array-grow)
                 (safe-incf *max-symbol-to-fixnum*
                            1 symbol-to-fixnum-create)
                 *max-symbol-to-fixnum*))))))

(defun-one-output symbol-to-fixnum (s)
  (check-type s symbol)
  (let ((g (gethash s *memoize-info-ht*)))
    (if g (access memoize-info-ht-entry g :num)
      (error "(symbol-to-fixnum ~s).  Illegal symbol." s))))

(defun-one-output fixnum-to-symbol (n)
  (check-type n fixnum)
  (or (gethash n *memoize-info-ht*)
      (error "(fixnum-to-symbol ~s). Illegal number." n)))

(defun-one-output coerce-index (x)
  (if (and (typep x 'fixnum)
           (>= x 0)
           (< x (length *memoize-call-array*)))
      x
    (symbol-to-fixnum x)))







(defun-one-output memoize-eval-compile (def)
  (unless (and (consp def)
               (eq 'defun (car def))
               (consp (cdr def))
               (symbolp (cadr def)))
    (error "MEMOIZE-EVAL-COMPILE:  Bad input:~%~s." def))
  (compile (eval def))
  nil)

(defun-one-output memoizedp-raw (fn)
  (and (symbolp fn)
       (values (gethash fn *memoize-info-ht*))))

(defg *hons-gentemp-counter* 0)

(defun-one-output hons-gentemp (root)
  (check-type root string)
  (loop
   (safe-incf *hons-gentemp-counter* 1 hons-gentemp)
   (let ((name (ofn "HONS-G-~s,~s" root *hons-gentemp-counter*)))
     (multiple-value-bind (sym status)
         (intern name (find-package "ACL2_INVISIBLE"))
       (if (null status) (return sym))))))

(defun-one-output st-lst (st)

; ST-LST returns a symbol whose value is a list in which are saved the
; names of the memoize tables that will be set to nil whenever the
; stobj st is changed.

  (check-type st symbol)
  (intern (ofn "HONS-S-~s,~s"
               (package-name (symbol-package st))
               (symbol-name st))
          (find-package "ACL2_INVISIBLE")))

(defun-one-output dcls (l)
     (loop for dec in l nconc
           (let ((temp
                  (if (consp dec)
                      (loop for d in (cdr dec) nconc
                            (if (and (consp d) (eq (car d) 'ignore))
                                nil
                              (cons d nil))))))
             (if temp (cons (cons 'declare temp) nil)))))


; PRINE  - princ eviscerated

(defg *assoc-eq-hack-ht* (hl-mht :test 'eql))
(declaim (hash-table *assoc-eq-hack-ht*))

(defn assoc-eq-hack (x y)
  (cond ((atom y) nil)
        (t (let ((h (gethash y *assoc-eq-hack-ht*)))
             (cond (h (gethash x (the hash-table h)))
                   (t (setq h (hl-mht :test 'eq))
                      (setf (gethash y *assoc-eq-hack-ht*)
                            h)
                      (loop for pair in y do
                            (setf (gethash (car pair)
                                           (the hash-table h))
                                  pair))
                      (gethash x (the hash-table h))))))))

(defun abbrev (x &optional
                (level *print-level*)
                (length *print-length*))
  (cond ((atom x) x)
        ((eql level 0) '?)
        ((eql length 0) '?)
        (t (let ((pair (assoc-eq-hack
                        x (table-alist 'evisc-table
                                       (w *the-live-state*)))))
             (cond (pair (cdr pair))
                   (t (let ((a (abbrev (car x)
                                       (and level (1- level))
                                       length))
                            (d (abbrev (cdr x)
                                       level
                                       (and length (1- length)))))
                        (cond ((and (eq a (car x))
                                    (eq d (cdr x)))
                               x)
                              ((and (eq a '?)
                                    (eq d '?))
                               '?)
                              (t (cons a d))))))))))

(defun prine (obj &optional stream)
  (let ((*print-pretty* nil))
    (princ (abbrev obj *print-level* *print-length*) stream)))


(defun prine-alist (obj &optional stream)

  ; Does not print the last atom.
  ; Prints "=" between pairs.

  (let ((*print-pretty* t))
    (let ((max 6))
      (cond
       ((loop for tail on obj always
              (and
               (consp (car tail))
               (atom (caar tail))
               (setq max (max max
                              (if (symbolp (caar tail))
                                  (length (symbol-name (caar tail)))
                                0)))))
        (loop for tail on obj do
              (cond ((eq obj tail) (write-char #\Space stream))
                    (t (oft "~&    ")))
              (princ (caar tail) stream)
              (loop for i fixnum below
                    (- max
                       (if (symbolp (caar tail))
                           (length (symbol-name (caar tail)))
                         0))
                    do (write-char #\Space stream))
              (princ " = ")
              (prine (cdar tail) stream)))
       (t (prine obj stream))))))

; MEMOIZE-FN

(defun-one-output mf-trace-exit (fn nrv ans)
  (oftr "~%< ~s " fn)
  (cond ((> nrv 1)
         (oftr "returned ~@r values:" nrv)
         (loop for i fixnum from 1 to nrv do
               (oftr "~%~@r.~8t  " i)
               (prine (car ans) *trace-output*)))
        (t (prine ans *trace-output*)))
  (oftr ")~%"))

(defg *memoize-fn-signature-error*
  "
  Memoize-fn: could not determine a signature for ~a.~%~
  To assert the (number-of-inputs . number-of-outputs)~%~
  signature of ~:*~a, put a cons of two numbers in the hash-table ~%~
  *NUMBER-OF-ARGUMENTS-AND-VALUES-HT* under ~:*~a.  For example, ~%~
  do (setf (gethash '~:*~a *NUMBER-OF-ARGUMENTS-AND-VALUES-HT*)
         '(3 . 1))")

(defg *sort-to-from-by-calls* nil)

(defvar *memoize-use-attachment-warning-p* t)

(defun memoize-use-attachment-warning (fn at-fn)
  (when *memoize-use-attachment-warning-p*
    (let ((state *the-live-state*))
      (warning$ 'top-level "Attachment"
                "Although the function ~x0 is memoized, a result is not being ~
                 stored because ~@1.  Warnings such as this one, about not ~
                 storing results, will remain off for all functions for the ~
                 remainder of the session unless the variable ~x2 is set to a ~
                 non-nil value in raw Lisp."
                fn
                (mv-let (lookup-p at-fn)
                        (if (consp at-fn)
                            (assert$ (eq (car at-fn) :lookup)
                                     (mv t (cdr at-fn)))
                          (mv nil at-fn))
                        (cond (lookup-p
                               (msg "a stored result was used from a call of ~
                                     memoized function ~x0, which may have ~
                                     been computed using attachments"
                                    at-fn))
                              (t
                               (msg "an attachment to function ~x0 was used ~
                                     during evaluation of one of its calls"
                                    at-fn))))
                '*memoize-use-attachment-warning-p*))
    (setq *memoize-use-attachment-warning-p* nil)))

(defun-one-output memoize-fn-suffix (str sym)
  (check-type str string)
  (check-type sym symbol)
  (let ((spkn (package-name (symbol-package sym)))
        (sn (symbol-name sym)))
    (format nil "~s,~s,~s" str spkn sn)))


(defun-one-output mis-ordered-commutative-args (x y)
  #-Clozure
  ;; [Jared]: Lisps besides Clozure don't have static conses so we can't
  ;; reorder arguments based on their indices.  It's possible we could do
  ;; something like sort based on address, maybe, but I haven't thought about
  ;; it.
  (declare (ignore x y))
  #-Clozure
  nil
  #+Clozure
  (cond ((eql x y) nil)
        (t (let ((idx (or (ccl::%staticp x)
                          (and (typep x 'fixnum) x))))
             (cond (idx
                    (let ((idy (or (ccl::%staticp y)
                                   (and (typep y 'fixnum) y))))
                      (cond (idy (< (the fixnum idy)
                                    (the fixnum idx)))
                            ((rationalp y)
                             (< y (the fixnum idx))))))
                   ((rationalp x)
                    (let ((idy (or (ccl::%staticp y)
                                   (and (typep y 'fixnum) y))))
                      (cond (idy (< (the fixnum idy)
                                    x))
                            ((rationalp y)
                             (< y x))))))))))

(defun our-function-lambda-expression (sym)
  (let ((temp (get sym 'acl2-saved-def)))
    (cond (temp (values temp t))
          (t (let* ((fn (symbol-function sym))
                    (lam (and fn (function-lambda-expression fn))))
               (cond (lam (values lam nil))
                     (t (values nil nil))))))))

(defun memoize-look-up-def (fn cl-defun inline wrld)
  ;; [Jared] I *think* what is going on here is the following:
  ;;
  ;; When you call MEMOIZE-FN you can give a :cl-defun argument.  This defaults
  ;; to :default, which means: "Look up the function's definition from the world
  ;; or from the Lisp."
  ;;
  ;; But you can alternately provide an explicit definition.  I'm not sure
  ;; quite what the format of this is supposed to be.  It looks like this
  ;; definition gets recorded in the info-table for fn, and maybe it gets used
  ;; in restoring and turning memoize on/off, etc.
  (cond ((eq cl-defun :default)
         (if inline
             (cond
              ((not (fboundp fn))
               (error "MEMOIZE-LOOK-UP-DEF: ** ~a is undefined." fn))

              ((let ((def (cltl-def-from-name fn wrld)))
                 (cond (def (assert (eq (car def) 'defun))
                            (cdr def)))))

              ((multiple-value-bind
                   (def flg)
                   (our-function-lambda-expression fn)
                 (cond (flg (cdr def))
                       (def (assert (eq (car def) 'lambda))
                            def))))

              (t
               #+Clozure
               (unless (and ccl::*save-source-locations*
                            ccl::*fasl-save-definitions*)
                 (format t "; Check the settings of CCL::*SAVE-SOURCE-LOCATIONS* ~
                       and CCL::*FASL-SAVE-DEFINITIONS*."))
               (error "MEMOIZE-LOOK-UP-DEF: ** Cannot find a definition for ~
                       ~a via ACL2 or OUR-FUNCTION-LAMBDA-EXPRESSION."
                      fn)))
           nil))
        ((eq (car cl-defun) 'defun)
         (cdr cl-defun))
        (t
         cl-defun)))

(defun fix-time (ticks ctx)
  (declare (type integer ticks))
  (if (and (<= 0 ticks)
           (< ticks (* 864000 ;; 10 days, in seconds
                       *float-ticks/second*)))
      ticks
    (progn (format t "Ignoring time increment of ~a sec for ~a~%"
                   (/ ticks *float-ticks/second*) ctx)
           0)))

(defg *memoize-init-done* nil)

(defun memoize-fn (fn &key (condition t) (inline t) (trace nil)
                      (cl-defun :default)
                      (formals :default)
                      (stobjs-in :default)
                      (stobjs-out :default)
                      (commutative nil)
                      (specials nil)
                      (forget nil)
                      (memo-table-init-size '60)
                      (aokp nil)
                      &aux (wrld (w *the-live-state*)))

  "The documentation for MEMOIZE-FN is very incomplete.  One may
  invoke (MEMOIZE-FN fn) on the name of a Common Lisp function FN from
  outside the ACL2 loop to get results of possible interest in terms
  of memoization activity and profiling information.  MEMOIZE-FN
  already has a dozen parameters.

  MEMOIZE-FN replaces the SYMBOL-FUNCTION for the symmbol FN with
  'enhanced' raw Common Lisp code that, supposedly, does not affect
  the value returned by FN but may make some notes and may even obtain
  some return values by remembering them from a previous call.

  If the CONDITION parameter is not NIL, then whenever FN is called,
  and there is not as yet any value remembered for a call of FN on the
  given arguments, then if the evaluation of the CONDITION parameter
  is not NIL, the values that are computed for FN on the given
  arguments will be saved under the given arguments.  If the CONDITION
  parameter is the name of an ACL2 function, the body of that function
  is used as the condition.

  If the INLINE parameter is T, then when MEMOIZE-FN creates a new
  body for FN, we place the old body of FN within the new body, i.e.,
  'in line'.  However, if the INLINE parameter is NIL, then we place
  code that calls the existing SYMBOL-FUNCTION for FN within the new
  body.  One might well argue that our parity for the INLINE parameter
  to MEMOIZE-fn is backwards, but we don't think so.

  The TRACE parameter to MEMOIZE-FN may be T, NIL, :INLINE, or
  :NOTINLINE.

  One may lie to MEMOIZE-FN to force the memoization of a function
  that has ACL2's state as an explicit parameter by using fraudulent
  FORMALS, STOBJS-IN, and STOBJS-OUT parameters to MEMOIZE-FN.

  If the COMMUTATIVE parameter is not NIL, then the two arguments may
  be swapped before further processing.  We hope/presume that ACL2
  will have been used first to prove that commutativity.

  If the CL-DEFN parameter is not NIL, we pretend that the current
  body of FN is that parameter, and similarly for FORMALS, STOBJS-IN,
  and STOBJS-OUT.

  If FN is a raw Common Lisp function and not an ACL2-approved
  function, it may make reference to a variable, say S, that has a
  SPECIAL binding, in which case one needs to consider what in the
  world the meaning is for memoizing such a function at all.  If S is
  a member of the SPECIALS parameter, then it is assumed that FN does
  not alter but only refers to S.  MEMOIZE-FN acts as though FN had S
  as an extra argument for purposes of memoization.

  If the FORGET parameter is not NIL, the pons and memo tables of FN
  are discarded at the end of every outermost call of FN."

; MIS-ORDERED-COMMUTATIVE-ARGS apparently, but only apparently,
; introduces nondeterminism into the values returned by ACL2 functions
; redefined with MEMOIZE-FN, something highly suspicious because it
; can so easily lead to a contradition.

; We believe that the use of the nondeterministic function
; MIS-ORDERED-COMMUTATIVE-ARGS in the memoization of an ACL2 function
; of two arguments that has been proven commutative is justified by
; the fact that the memoized function will return, modulo EQUAL, the
; same result regardless of what MIS-ORDERED-COMMUTATIVE-ARGS returns,
; and hence the nondeterminism cannot be detected by the ACL2 logic.

; The :CONDITION parameter of MEMOIZE-FN can either be T, or a
; function symbol defined by the user within the ACL2 loop, or a LISTP
; (CONSP or NIL).  In the last case we think of the condition as an
; expression in the formals of FN.  If the :INLINE parameter T, then
; the body of FN is placed inline in the memoized definition;
; otherwise, a funcall of the original function is placed there.


  #-hons
  (return-from memoize-fn
               (progn (when (not (zerop *ld-level*))
                        (warning$ 'memoize nil
                                  "No change for function ~x0: Memoization ~
                                   requests are ignored in this ACL2 ~
                                   executable because it is not hons-enabled."
                                  fn))
                      fn))

  (when (equal condition *nil*)
    (setq condition nil))

  (maybe-untrace! fn) ; See the comment about Memoization in trace$-def.
  (with-warnings-suppressed

; Big old bunch of error checking...


   (unless *memoize-init-done*
     (error "Memoize-fn:  *MEMOIZE-INIT-DONE* is still nil."))

   (unless (symbolp fn)
     (error "Memoize-fn: ~s is not a symbol." fn))

   (unless (or (fboundp fn) (not (eq cl-defun :default)))
     (error "Memoize-fn: ~s is not fboundp." fn))

   (when (or (macro-function fn)
             (special-operator-p fn)
             (and (fboundp 'compiler-macro-function) ; for GCL as of 5/2013
                  (compiler-macro-function fn)))
     (error "Memoize-fn: ~s is a macro or a special operator or has a ~
             compiler macro." fn))

   (when (never-memoize-p fn)
     (error "Memoize-fn: ~s must never be memoized" fn))

   (when (memoizedp-raw fn)
     (format t "; Memoize-fn: ** Warning: ~s is currently memoized.~%~
                ; We will first unmemoize it, then memoize it again."
             fn)
     (unmemoize-fn fn))

   (when (member fn (eval '(trace)))
     (format t "; Memoize-fn:  Untracing ~s before memoizing it." fn)
     (eval `(untrace ,fn)))

; TRACE, UNTRACE, OLD-TRACE, and OLD-UNTRACE are macros that get
; redefined sometimes.  So we use EVAL in calling them.

   #+Clozure
   (when (ccl::%advised-p fn)
     (error "~%; Memoize-fn: Please unadvise ~s before calling memoize-fn on ~
             it." fn))

   (when (and (fboundp 'old-trace)
              (member fn (eval '(old-trace))))
     (format t "; Memoize-fn:  Old-untracing ~s before memoizing it." fn)
     (eval `(old-untrace ,fn)))

   (when (eq fn 'return-last)
     (error "Memoize-fn: RETURN-LAST may not be memoized."))

   (when (getprop fn 'constrainedp nil 'current-acl2-world wrld)
     (error "Memoize-fn: ~s is constrained; you may instead wish to memoize a ~
             caller or to memoize its attachment (see :DOC defattach)."
            fn))

   ;; Doesn't this get checked below?  See the lambda-list intersection thing
   #+Clozure
   (when (multiple-value-bind (req opt restp keys)
             (ccl::function-args (symbol-function fn))
           (or restp
               keys
               (not (integerp req))
               (not (eql opt 0))))
     (error "Memoize-fn: ~a has non-simple arguments." fn))


   (let*
       ((cl-defun (memoize-look-up-def fn cl-defun inline wrld))

        (formals
         ;; Magic code to try to figure out what the formals of the function are.
         ;; For ACL2 functions this works via looking up the 'formals property
         ;; For raw Lips functions we may be able to extract the formals from the
         ;; cl-defun above, or we may generate a list (X1 ... XN) in some cases?
         (if (eq formals :default)
             (let ((fo (getprop fn 'formals t 'current-acl2-world wrld)))
               (if (eq fo t)
                   (if (consp cl-defun)
                       (cadr cl-defun)
                     (let ((n (number-of-arguments fn)))
                       (if n
                           (loop for i fixnum below n
                                 collect (ofni "X~a" i))
                         (error *memoize-fn-signature-error* fn))))
                 fo))
           formals))

        (stobjs-in
         ;; Either the ACL2 stobjs-in property or (T T T T ...) for the number
         ;; of formals that we inferred the function has.
         (if (eq stobjs-in :default)
             (let ((s (getprop fn 'stobjs-in t 'current-acl2-world
                               wrld)))
               (if (eq s t) (make-list (len formals)) s))
           stobjs-in))

        (stobjs-out
         ;; Either the ACL2 stobjs-out property or (T T T T ...) for the number
         ;; of return values that we inferred the function has.
         (if (eq stobjs-out :default)
             (let ((s (getprop fn 'stobjs-out t 'current-acl2-world wrld)))
               (if (eq s t)
                   (let ((n (number-of-return-values fn)))
                     (cond (n (make-list n))
                           ((and (null condition)
                                 (null trace))
                            (list nil nil))
                           (t (error
                               "Memoize-fn: cannot determine the ~
                               number of return values of ~a.~%~
                               You may put a cons of ~
                               two numbers in the hash-table~%~
                               *NUMBER-OF-ARGUMENTS-AND-VALUES-HT* ~
                               under ~a. ~%For example, do (setf ~
                               (gethash '~a ~
                               *NUMBER-OF-ARGUMENTS-AND-VALUES-HT*) ~
                               '(~a . 1))"
                               fn fn fn (len stobjs-in)))))
                 s))
           stobjs-out)))

     ;; Not sure why this check is necessary or useful
     (unless (and (symbol-listp formals)
                  (no-duplicatesp formals)
                  (loop for x in formals never (constantp x)))
       (error "Memoize-fn: FORMALS, ~a, must be a true list of distinct, ~
               nonconstant symbols."
            formals))

     (when (intersection lambda-list-keywords formals)
       (error "Memoize-fn: FORMALS, ~a, may not intersect ~
               LAMBDA-LIST-KEYWORDS." formals))

     ;; Don't memoize functions involving state.  Fair enough.
     ;; Can you memoize functions with other stobjs??
     (when (and condition (or (member 'state stobjs-in)
                              (member 'state stobjs-out)))
       (error "Memoize-fn:  ~s uses STATE." fn))


     (let*
         ((fnn (symbol-to-fixnum-create fn)) ; performance counting; see memoize-call-array
          (2mfnn (* *2max-memoize-fns* fnn)) ; performance counting; see memoize-call-array

          (*acl2-unwind-protect-stack*
           (or *acl2-unwind-protect-stack*
               (cons nil *acl2-unwind-protect-stack*)))

          (old-fn (if (fboundp fn) (symbol-function fn)))

          (body (if (or inline (null old-fn))
                    (car (last cl-defun))
                  `(funcall #-gcl ,old-fn
                            #+gcl ',old-fn ; old-fn could be (lisp:lambda-block ...)
                            ,@formals)))


          (body-name (make-symbol "BODY-NAME"))
          (body-call (list body-name))

          (condition-body
           (cond ((booleanp condition) condition)
                 ((symbolp condition)
                  ;; Bizarre thing where the condition can be just the name of an ACL2 function,
                  ;; see the documentation above
                  (car (last (cltl-def-from-name condition wrld))))
                 (t condition)))

          (dcls (dcls (cddr (butlast cl-defun))))
          (start-time (let ((v (hons-gentemp
                                (memoize-fn-suffix "START-TIME-" fn))))
                        (eval `(prog1 (defg ,v -1)
                                 (declaim (type integer ,v))))))
          (tablename
           ;; Submits the defg form and returns the crazy name that gets generated.
           (eval `(defg
                    ,(hons-gentemp (memoize-fn-suffix "MEMOIZE-HT-FOR-" fn))
                    nil)))
          (ponstablename
           ;; Submits the defg form and returns the crazy name that gets generated.
           (eval `(defg
                    ,(hons-gentemp (memoize-fn-suffix "PONS-HT-FOR-" fn))
                    nil)))

          (localtablename (make-symbol "TABLENAME"))
          (localponstablename (make-symbol "PONSTABLENAME"))
          (sts

; Here we support memoize-flush, which keeps memoize tables coherent in the
; presence of user-defined stobjs.  For each (user-level) stobj input name, st,
; we collect up the variable (st-lst st), whose value is the list of names of
; memoize tables that need to be cleared whenever that stobj changes.  Below,
; we will push the present function's table name onto each of these lists.

; Ultimately, stobj updates are made by stobj primitives.  After the stobj
; primitive for stobj st makes an update, the memo table for a function f
; taking st as its nth argument (say) is no longer valid for saved calls of f
; for which the nth argument is st.  Because of congruent stobjs and abstract
; stobjs, that nth argument need not be st, and we believe that in principle,
; we could restrict flushing of memo table entries of f to those whose nth
; argument is eq to the stobj being updated (whether st, congruent to st, or an
; abstract stobj whose concrete stobj is congruent to st).  But for now we take
; the coarser approach, which has the advantage that we simply throw away the
; memo-table for f when flushing, leaving it to be garbage collected; see
; memoize-flush1.

           (and condition ; else no memo table usage, so skip flushing
                (remove-duplicates-eq
                 (loop for st in (union stobjs-in stobjs-out)
                       when st
                       collect
                       (assert$
                        (not (and condition
                                  (eq st 'state))) ; see memoize-table-chk
                        (st-lst (congruent-stobj-rep

; In the case that st is an abstract stobj, we replace it with the
; corresponding concrete stobj before getting a canonical (congruent)
; representative; see the rather long comment just above that mentions
; "abstract" stobjs.

                                 (or (concrete-stobj st wrld)
                                     st)
                                 wrld)))))))

          ;; Number of arguments.  Specials only matter for common lisp functions, see the notes above in memoize-fn.
          ;; Basically if the function reads from specials we want to count them as args.
          (nra (+ (len formals) (len specials)))

          def
          success)
       (let*
           ((mf-trace-exit
             ;; Ignore this, just some kind of tracing...
             (and trace `((mf-trace-exit ',fn ,(length stobjs-out)
                                         ,*mf-ans*))))
            (mf-record-mht
             ;; performance counting, see memoize-call-array
             (and *record-mht-calls*
                  `((safe-incf (aref ,*mf-ma* ,2mfnn) 1 ,fn))))
            (mf-record-hit
             ;; performance counting, see memoize-call-array
             (and *record-hits* condition-body
                  `((safe-incf (aref ,*mf-ma*
                                     ,(+ 2mfnn *ma-hits-index*))
                               1 ,fn))))
            (lookup-marker (cons :lookup fn))



            (body3
             ;; Main part of the new function definition...

             `(let (,*mf-ans* ,*mf-args* ,*mf-ans-p*)
                (declare (ignorable ,*mf-ans* ,*mf-args* ,*mf-ans-p*))

                (cond
                 ((not ,condition-body)
                  ,@mf-record-hit ; sort of a hit
                  ,(if (not trace)
                       body-call
                     (if (cdr stobjs-out)
                         `(progn
                            (setq ,*mf-ans*
                                  (multiple-value-list ,body-call))
                            ,@mf-trace-exit
                            (values-list ,*mf-ans*))
                       `(progn (setq ,*mf-ans* ,body-call)
                               ,@mf-trace-exit
                               ,*mf-ans*))))


                 ,@(and
                    condition-body
                    `((t

                       ;; reinitialize tables if they don't exist...
                       (when
                           (null ,tablename)
                         ,@mf-record-mht
                         (setq ,tablename (make-initial-memoize-hash-table ',fn ,memo-table-init-size))

                         ,@(if (> nra 1) ; number of arguments
                               `((setq ,ponstablename
                                       (make-initial-memoize-pons-table ',fn ,memo-table-init-size)))))


                       ;; To avoid a remotely possible parallelism gethash error.  (jared: what?!?)
                       ,@(if (> nra 1)
                             `((setq ,localponstablename
                                     (or ,ponstablename
                                         ;; BOZO should this be a make-initial-memoize-pons-table?
                                         (hl-mht)))))


                       ;; Generate the pons key... if there's just one arg, pist* just returns the arg and
                       ;; doesn't do any ponsing.

                       (setq ,*mf-args* (pist* ,localponstablename ,@formals ,@specials))


                       ;; dunno what this is for... maybe we're binding a localtablename variable to avoid
                       ;; doing special lookups or some such?

                       (setq ,localtablename
                             ;; BOZO should this be a make-initial-memoize-hash-table?
                             (or ,tablename (hl-mht)))


                       ;; this is the lookup of the memoized result.

                       (multiple-value-setq
                           (,*mf-ans* ,*mf-ans-p*)
                         ,(let ((gethash-form
                                 `(gethash ,*mf-args*
                                           (the hash-table ,localtablename))))
                            (cond (aokp `(cond
                                          (*aokp* ,gethash-form)
                                          (t (mv nil nil))))
                                  (t gethash-form))))



                       (cond
                        (,*mf-ans-p*

                         ;; Memoized lookup succeeds.  Do profiling things, return answer...

                         ,@(when aokp `((update-attached-fn-called ',lookup-marker)))
                         ,@(if trace `((oftr "~% ~s remembered." ',fn)))
                         ,@mf-record-hit
                         ,@(cond ((null (cdr stobjs-out))
                                  `(,@mf-trace-exit ,*mf-ans*))
                                 (t
                                  ;; No idea what this is doing...
                                  (let ((len-1 (1- (length stobjs-out))))
                                    `(,@(and trace
                                             `(progn
                                                (let* ((,*mf-ans* (append (take ,len-1 ,*mf-ans*)
                                                                          (list (nthcdr ,len-1 ,*mf-ans*)))))
                                                  ,@mf-trace-exit)))
                                      ,(cons
                                        'mv
                                        (nconc (loop for i fixnum below len-1 collect `(pop ,*mf-ans*))
                                               (list *mf-ans*))))))))


                        (t

                         ;; Memoized lookup failed.  Need to run the function and get its results...

                         ,(let* ((vars
                                  ;; Make variables (O0 O1 ... 0N) for the outputs?  Don't really understand what stobjs-out is
                                  ;; for here...
                                  (loop for i fixnum below (if (cdr stobjs-out) (length stobjs-out) 1) collect (ofni "O~a" i)))

                                 (prog1-fn (if (cdr stobjs-out) 'multiple-value-prog1 'prog1))
                                 (mf-trace-exit+
                                  (and mf-trace-exit
                                       `((let ((,*mf-ans* ,(if stobjs-out `(list* ,@vars) (car vars))))
                                           ,@mf-trace-exit)))))

                            `(let (,*attached-fn-temp*)
                               (mv?-let
                                ,vars
                                (let (*attached-fn-called*)
                                  ;; This is where the actual function is being run.  The 01...0N vars are being bound to
                                  ;; the results...
                                  (,prog1-fn
                                   ,body-call
                                   (setq ,*attached-fn-temp* *attached-fn-called*)))
                                (progn
                                  (cond
                                   ,@(and (not aokp)
                                          `((,*attached-fn-temp*
                                             (memoize-use-attachment-warning ',fn ,*attached-fn-temp*))))
                                   (t
                                    ;; Actually install the results
                                    (setf (gethash ,*mf-args* (the hash-table ,localtablename))
                                          (list* ,@vars))))
                                  (update-attached-fn-called ,*attached-fn-temp*)
                                  ,@mf-trace-exit+
                                  (mv? ,@vars)))))))))))))


            (body2
             ;; Bunch of extra profiling stuff wrapped around body3.

             `(let ((,*mf-old-caller* *caller*)
                    #+Clozure
                    ,@(and *record-bytes*
                           `((,*mf-start-bytes*
                              (heap-bytes-allocated))))
                    ;; [Jared]: removing this, hons tracking hasn't worked since hl-hons
                    ;; ,@(and *record-hons-calls*
                    ;;        `((,*mf-start-hons* *hons-call-counter*)))
                    ,@(and *record-pons-calls*
                           `((,*mf-start-pons* *pons-call-counter*))))
                (declare
                 (ignorable
                  #+Clozure
                  ,@(and *record-bytes* `(,*mf-start-bytes*))
                  ;; ,@(and *record-hons-calls* `(,*mf-start-hons*))
                  ,@(and *record-pons-calls* `(,*mf-start-pons*)))
                 (type fixnum
                       ,*mf-old-caller*
                       ;; ,@(and *record-hons-calls* `(,*mf-start-hons*))
                       ,@(and *record-pons-calls* `(,*mf-start-pons*))
                       #+Clozure
                       ,@(and *record-bytes* `(,*mf-start-bytes*))))
                (unwind-protect
                    (progn
                      (setq ,start-time ,(if *record-time*
                                             '(internal-real-time)
                                           '0))
                      (setq *caller* ,2mfnn)
                      ,body3)
                  ;; [Jared]: removing this, hons tracking hasn't worked since hl-hons
                  ;; ,@(and *record-hons-calls*
                  ;;        `((safe-incf (aref ,*mf-ma* ,(+ *ma-hons-index* 2mfnn))
                  ;;          (the mfixnum (- *hons-call-counter* ,*mf-start-hons*)) ,fn)))
                  ,@(and *record-pons-calls*
                         `((safe-incf
                            (aref ,*mf-ma* ,(+ *ma-pons-index* 2mfnn))
                            (the mfixnum
                              (- *pons-call-counter*
                                 ,*mf-start-pons*))
                            ,fn)))
                  #+Clozure
                  ,@(and *record-bytes*
                         `((safe-incf
                            (aref ,*mf-ma* ,(+ *ma-bytes-index* 2mfnn))
                            (the mfixnum
                              (- (heap-bytes-allocated)
                                 ,*mf-start-bytes*))
                            ,fn)))
                  ,@(and *record-time*
                         `((safe-incf
                            (aref ,*mf-ma*
                                  (the mfixnum (1+ ,*mf-count-loc*)))
                            (the integer
                              (fix-time (the integer (- (internal-real-time)
                                                        ,start-time))
                                        ',fn))
                            ,fn)))
                  ,@(and forget

; Below, we "clear" the tables by setting them to nil, rather than by calling
; clrhash.  The latter approach would probably avoid reallocation of space, but
; we suspect that a gain in space efficiency may be offset by a loss in time
; efficiency.  The present approach has been working, so we prefer not to
; change it.  Below is just a little space analysis.

; When we evaluated (defconstant *a* (make-list 1000)) in raw Lisp (CCL) and
; then ran (time$ (bad-lisp-objectp *a*)), we saw about 71K bytes allocated,
; which dropped to just 1,136 bytes after evaluating (unmemoize-fn
; 'bad-lisp-objectp).  Then we evaluated (memoize-fn 'bad-lisp-objectp) -- this
; time without a :forget argument -- and found about 71K bytes allocated on the
; first timing of (bad-lisp-objectp *a*), but only 1,136 bytes allocated on
; subsequent evaluations, presumably because we weren't starting from scratch.
; We suspect that the byte allocation on subsequent runs may have been well
; under 71K even after memoizing with :forget t, if the tables had been cleared
; with clrhash rather than being blown away as is done just below.

                         `((setq ,tablename nil)
                           ,@(if (> nra 1)
                                 `((setq ,ponstablename nil)))))
                  (setq ,start-time -1)
                  (setq *caller* ,*mf-old-caller*)))))

         (setq def
               `(defun ,fn ,formals ,@dcls
                  ,@(if trace
                        (if (member trace '(notinline inline))
                            `((declare (,trace ,fn)))
                          `((declare (notinline ,fn)))))
                  (declare (ignorable ,@formals ,@specials))
                  ,@(and commutative
                         `((cond ((mis-ordered-commutative-args
                                   ,(car formals)
                                   ,(cadr formals))
                                  (rotatef ,(car formals)
                                           ,(cadr formals))))))
                  ,@(and trace
                         `((oftr "~%(> ~s (" ',fn)
                           ,@(loop for v in (append formals specials)
                                   append
                                   `((oftr "~& ~s = " ',v)
                                     (prine ,v *trace-output*)))
                           (oftr "~& )")))
                  (let* ((,*mf-count-loc*
                          ,(if (or *record-calls* *record-time*)
                               `(the fixnum (+ *caller* (* 2 ,fnn)))
                             0))
                         (,*mf-ma* *memoize-call-array*)
                         ,localtablename ,localponstablename)
                    (declare (type fixnum ,*mf-count-loc*)
                             (ignorable ,*mf-count-loc* ,*mf-ma*
                                        ,localponstablename
                                        ,localtablename)
                             (type (simple-array mfixnum (*))
                                   ,*mf-ma*))
                    ,@(and *record-calls*
                           `((safe-incf (aref ,*mf-ma*
                                              ,*mf-count-loc*)
                                        1
                                        ,fn)))
                    (flet ((,body-name () ,body))
                      (if (eql -1 ,start-time)
                          ,body2
                        ,body3))))))
       (setf (gethash fn *number-of-arguments-and-values-ht*)
             (cons (length stobjs-in) (length stobjs-out)))
       (unwind-protect
           (progn
             (let ((ma *memoize-call-array*))
               (declare (type (simple-array mfixnum (*)) ma))
               (loop for i fixnum from 2mfnn
                     below (the fixnum (+ 2mfnn *2max-memoize-fns*))
                     unless (eql (aref ma i) 0)
                     do (setf (aref ma i) 0)))
             (memoize-eval-compile def)
             (setf (gethash fn *memoize-info-ht*)
                   (make memoize-info-ht-entry
                         :fn fn
                         :ext-anc-attachments
                         (and aokp (extended-ancestors fn wrld))
                         :tablename tablename
                         :ponstablename ponstablename
                         :old-fn old-fn
                         :memoized-fn (symbol-function fn)
                         :condition condition
                         :inline inline
                         :num fnn
                         :sts sts
                         :trace trace
                         :start-time start-time
                         :cl-defun cl-defun
                         :formals formals
                         :commutative commutative
                         :specials specials
                         :stobjs-in stobjs-in
                         :stobjs-out stobjs-out
                         :record-bytes      *record-bytes*
                         :record-calls      *record-calls*
                         :record-hits       *record-hits*
                         :record-hons-calls *record-hons-calls*
                         :record-mht-calls  *record-mht-calls*
                         :record-pons-calls *record-pons-calls*
                         :record-time       *record-time*
                         :forget            forget
                         :memo-table-init-size memo-table-init-size))
             (setf (gethash fnn *memoize-info-ht*) fn)
             (and condition (loop for s in sts do
                                  (push tablename
                                        (symbol-value s))))
             (setq success t))
         (unless success
           (setf (symbol-function fn) old-fn)
           (remhash fn *memoize-info-ht*)
           (remhash fnn *memoize-info-ht*)
           (and condition
                (loop for s in sts
                      when (eq tablename
                               (car (symbol-value
                                     (the symbol s))))
                      do (pop (symbol-value (the symbol s)))))
           ;; [Jared] is there some reason this shouldn't just be an error?
           (format t "Memoize-fn:  Failed to memoize ~s." fn)
           (setq fn nil))))))
  fn)

(defun-one-output unmemoize-fn (fn)
  #-hons
  (return-from unmemoize-fn
               (progn (when (not (zerop *ld-level*))
                        (warning$ 'unmemoize nil
                                  "No change for function ~x0: Unmemoization ~
                                   requests are ignored in this ACL2 ~
                                   executable because it is not hons-enabled."
                                  fn))
                      fn))
  (maybe-untrace! fn) ; See the comment about Memoization in trace$-def.
  (let* ((ma *memoize-call-array*)
         (l (memoizedp-raw fn)))
    (declare (type (simple-array mfixnum (*)) ma))
    (unless l (error "Unmemoize-fn: ~s is not memoized." fn))
    (let* ((num (the fixnum (access memoize-info-ht-entry l
                                    :num)))
           (tablename (and l (access memoize-info-ht-entry l
                                     :tablename)))
           (n2 (* num *2max-memoize-fns*))
           )
      (declare (fixnum num n2))

; Note: condition is a first-class ACL2 function, not to be messed
; with here.

      (let (#+Clozure (ccl:*warn-if-redefine-kernel* nil))
        (let ((old-fn (access memoize-info-ht-entry
                              l :old-fn)))
          (if old-fn
              (setf (symbol-function (the symbol fn)) old-fn)
            (fmakunbound fn))))
      (loop for i fixnum from n2
            below (the fixnum (+ n2 *2max-memoize-fns*))
            unless (eql (aref ma i) 0)
            do (setf (aref ma i) 0))
      (remhash fn *memoize-info-ht*)
      (remhash num *memoize-info-ht*)
      (setf (symbol-value (the symbol tablename)) nil)
      (setf (symbol-value
             (the symbol (access memoize-info-ht-entry
                                 l :ponstablename)))
            nil)
      (loop for s in (access memoize-info-ht-entry l :sts) do
            (when (boundp s)
              (setf (symbol-value (the symbol s))
                    (remove tablename (symbol-value
                                       (the symbol s))))))))
  fn)

(defun-one-output maybe-unmemoize (fn)

; We rely on the normal undoing mechanism (for :ubt etc.) to take care of
; unmemoization.  However, as a courtesy to users who memoize using raw Lisp,
; we provide and call this utility for unmemoizing functions that are not known
; to ACL2 (via the memoize-table) as being memoized.

  (when (and (memoizedp-raw fn)
             (not (cdr (assoc-eq fn (table-alist 'memoize-table
                                                 (w *the-live-state*))))))
    (unmemoize-fn fn)))

(defun-one-output memoized-functions ()
  ;; Get the names of all memoized functions as a list.
  (let (ans)
    (maphash (lambda (fn info)
               (declare (ignore info))
               (when (symbolp fn)
                 (push fn ans)))
             *memoize-info-ht*)
    ans))

(defun-one-output length-memoized-functions ()

  "(length-memoized-functions) returns the number of currently
  memoized/profiled functions."

  (values (floor (1- (hash-table-count (the hash-table
                                         *memoize-info-ht*)))
                 2)))

(defun-one-output unmemoize-all ()

  "(UNMEMOIZE-ALL) unmemoizes all currently memoized functions,
  including all profiled functions."

; WARNING: ACL2 users should probably avoid this function, using
; (clear-memo-table) in the ACL2 loop instead.

; A warning to would-be code improvers.  It would be a bad idea to
; redefine UNMEMOIZE-ALL to MAPHASH over *MEMOIZE-INFO-HT* because of
; the ANSI rules restricting which hash table entries may be modified
; during a MAPHASH.

  (loop for x in (memoized-functions) do (unmemoize-fn x)))

(defun-one-output memoize-info (k)

  "(MEMOIZE-INFO k) returns the settings of the various arguments to
  MEMOIZE-FN and the settings of the special variables that influence
  MEMOIZE-FN during the memoization of K."

  (let ((v (gethash k *memoize-info-ht*)))
    (and v
         (list (list (access memoize-info-ht-entry v :fn)
                     :condition
                     (access memoize-info-ht-entry v :condition)
                     :inline
                     (access memoize-info-ht-entry v :inline)
                     :trace
                     (access memoize-info-ht-entry v :trace)
                     :cl-defun
                     (access memoize-info-ht-entry v :cl-defun)
                     :formals
                     (access memoize-info-ht-entry v :formals)
                     :stobjs-in
                     (access memoize-info-ht-entry v :stobjs-in)
                     :specials
                     (access memoize-info-ht-entry v :specials)
                     :commutative
                     (access memoize-info-ht-entry v :commutative)
                     :stobjs-out
                     (access memoize-info-ht-entry v
                             :stobjs-out)
                     :forget
                     (access memoize-info-ht-entry v :forget)
                     :memo-table-init-size
                     (access memoize-info-ht-entry v
                             :memo-table-init-size))

               (list
                (access memoize-info-ht-entry v :record-bytes)
                (access memoize-info-ht-entry v :record-calls)
                (access memoize-info-ht-entry v :record-hits)
                (access memoize-info-ht-entry v
                        :record-hons-calls)
                (access memoize-info-ht-entry v
                        :record-mht-calls)
                (access memoize-info-ht-entry v
                        :record-pons-calls)
                (access memoize-info-ht-entry v :record-time))))))

(defun-one-output rememoize-all ()
  (let (l)
    (maphash
     (lambda (k v)
       (declare (ignore v))
       (when (symbolp k) (push (memoize-info k) l)))
     *memoize-info-ht*)
    (loop for x in l do (unmemoize-fn (caar x)))
    (gc$)
    (setq *max-symbol-to-fixnum*
          *ma-initial-max-symbol-to-fixnum*)
    (loop for x in l do
          (progv '(*record-bytes*
                   *record-calls*
                   *record-hits*
                   *record-hons-calls*
                   *record-mht-calls*
                   *record-pons-calls*
                   *record-time*)
              (cadr x)
            (apply 'memoize-fn (car x))))))

(defun-one-output uses-state (fn)
  (let* ((w (w *the-live-state*))
         (stobjs-in (getprop fn 'stobjs-in t 'current-acl2-world w))
         (stobjs-out (getprop fn 'stobjs-out t
                              'current-acl2-world w)))
    (or (and (consp stobjs-in) (member 'state stobjs-in))
        (and (consp stobjs-out) (member 'state stobjs-out)))))


(defun profile-fn (fn &rest r &key (condition nil) (inline nil)
                      &allow-other-keys)
  (apply #'memoize-fn fn
         :condition condition
         :inline inline
         r))

(defun-one-output profiled-functions ()

  ; The profiled functions are hereby arbitrarily defined as those
  ; produced by MEMOIZE-FN with null :CONDITION and :INLINE fields.

  (let (l)
    (maphash
     (lambda (k v)
       (when (and (symbolp k)
                  (null (access memoize-info-ht-entry v :condition))
                  (null (access memoize-info-ht-entry v :inline)))
         (push k l)))
     *memoize-info-ht*)
    l))

(defun-one-output unmemoize-profiled ()

  "UNMEMOIZE-PROFILED is a raw Lisp function.  (UNMEMOIZE-PROFILED)
  unmemoizes and unprofiles all functions currently memoized with
  :CONDITION=NIL and :INLINE=NIL."

  (loop for x in (profiled-functions) do
        (unmemoize-fn (car x))))



(defmacro memoize-on-raw (fn x)
  `(let* ((,*mo-f* ,fn)
          (,*mo-h* (memoizedp-raw ,*mo-f*)))
     (unless ,*mo-h*
       (error "~s is not memoized" ,*mo-f*))
     (let ((,*mo-o* (symbol-function (the symbol ,*mo-f*))))
       (unwind-protect
           (progn (setf (symbol-function (the symbol ,*mo-f*))
                        (access memoize-info-ht-entry ,*mo-h*
                                :memoized-fn))
                  ,x)
         (setf (symbol-function (the symbol ,*mo-f*)) ,*mo-o*)))))

(defmacro memoize-off-raw (fn x)
  `(let* ((,*mo-f* ,fn)
          (,*mo-h* (memoizedp-raw ,*mo-f*)))
     (unless ,*mo-h*
       (error "~s is not memoized" ,*mo-f*))
     (let ((,*mo-o* (symbol-function (the symbol ,*mo-f*))))
       (unwind-protect
           (progn (setf (symbol-function (the symbol ,*mo-f*))
                        (access memoize-info-ht-entry ,*mo-h*
                                :old-fn))
                  ,x)
         (setf (symbol-function (the symbol ,*mo-f*)) ,*mo-o*)))))

(defun-one-output memoize-condition (fn)
  (let ((x (gethash fn *memoize-info-ht*)))
    (if x
        (access memoize-info-ht-entry x :condition)
      nil)))

(defn global-restore-memoize ()
  (maphash (lambda (k l)
             (when (symbolp k)
               (setf (symbol-function k)
                     (access memoize-info-ht-entry l :memoized-fn))))
           *memoize-info-ht*))


; STATISTICS GATHERING AND PRINTING ROUTINES

(defg *memoize-summary-order-list*
  '(total-time number-of-calls)

  "*MEMOIZE-SUMMARY-ORDER-LIST* is a raw Lisp variable.  It is a list
  of functions that MEMOIZE-SUMMARY uses to sort all functions that
  are currently memoized in preparation for displaying information
  about them.  The order used is lexicographical, with the first order
  having the most weight.  Each order function takes one argument, a
  symbol, and returns a rational.

  The default is '(total-time number-of-calls).

  Options for the functions include:

     bytes-allocated
     bytes-allocated/call
     event-number
     execution-order
     hits/calls
     hons-calls
     pons-calls
     number-of-calls
     number-of-hits
     number-of-memoized-entries
     number-of-mht-calls
     symbol-name-order
     time-for-non-hits/call
     time/call
     total-time.
  ")

(defg *memoize-summary-limit* 20

  "*MEMOIZE-SUMMARY-LIMIT* is a raw Lisp variable whose value is the
  maximum number of functions upon which MEMOIZE-SUMMARY reports.  A
  NIL value means report on all.")

(defg *shorten-ht* (hl-mht :test 'eql))

(defn shorten (x n)
  (cond ((and (stringp x) (<= (length x) n))
         x)
        (t
         (let ((x
                ;; Jared -- ugh, this was using maybe-str-hash directly.  It
                ;; looks like X is supposed to be a string or symbol.  Here's
                ;; a dumb approximation of the previous behavior:
                (if (stringp x)
                    (hons-copy x)
                  x)))
           (cond ((gethash x *shorten-ht*))
                 (t (let ((*print-pretty* nil)
                          (*print-length* 10)
                          (*print-level* 5)
                          (*print-lines* 2))
                      (let ((str
                             (with-output-to-string
                               (s)
                               (cond ((stringp x) (princ x s))
                                     (t (prin1 x s))))))
                        (setf (gethash x *shorten-ht*)
                              (cond ((<= (length str) n) str)
                                    ((setf (gethash x *shorten-ht*)
                                           (concatenate
                                            'string
                                            (subseq str 0 (max 0 n))
                                            "...")))))))))))))

(defg *memoize-summary-order-reversed* nil

  "*MEMOIZE-SUMMARY-ORDER-REVERSED* is a raw Lisp variable.  When it
  is not NIL, then MEMOIZE-SUMMARY reports on functions in order from
  least to greatest.")

(defg *print-alist-width* 45)

(defun-one-output print-alist (alist separation)
  (check-type separation (integer 0))
  (setq alist
        (loop for x in alist collect
              (progn
                (check-type x
                            (cons (or string symbol)
                                  (cons (or string (integer 0))
                                        null)))
                (list (shorten (car x) *print-alist-width*)
                      (if (integerp (cadr x))
                          (ofnum (cadr x))
                        (cadr x))))))
  (let* ((max1 (loop for x in alist maximize (length (car x))))
         (max2 (loop for x in alist maximize (length (cadr x))))
         (width (max (or *print-right-margin* 70)
                     (+ separation max1 max2))))
    (loop for x in alist do
          (fresh-line)
          (princ (car x))
          (loop for i
                below (- width (+ (length (car x))
                                  (length (cadr x))))
                do (write-char #\Space))
          (princ (cadr x))))
  nil)


; VERY-UNSAFE-INCF

(defmacro very-unsafe-incf (x inc &rest r)

; returns NIL !

  (declare (ignore r))

  (unless (symbolp x)
    ;; Compile-time sanity check
    (error "very-unsafe-incf should only be used on symbols, not ~a" x))

  `(locally (declare (type mfixnum ,x))
            (setq ,x (the mfixnum (+ ,x (the mfixnum ,inc))))
            nil))

(defmacro very-very-unsafe-aref-incf (ar loc)
 `(setf (aref (the (simple-array mfixnum (*)) ,ar) ,loc)
        (the mfixnum (1+ (aref (the (simple-array mfixnum (*)) ,ar)
                              ,loc)))))


(defun-one-output pons-summary ()
  (our-syntax-nice
   (let ((sssub 0) (nponses 0) (nsubs 0) (nponstab 0))
     (declare (type mfixnum sssub nponses nsubs))
   (oft "(defun pons-summary~%")
   (maphash
    (lambda (k v)
      (cond ((symbolp k)
             (let ((tab (symbol-value (access memoize-info-ht-entry v
                                              :ponstablename))))
               (when tab
                 (very-unsafe-incf nponstab 1 pons-summary)
                 (maphash
                  (lambda (k v) (declare (ignore k))
                    (cond
                     ((not (listp v))
                      (very-unsafe-incf
                       sssub
                       (hash-table-size (the hash-table v))
                       pons-summary)
                      (very-unsafe-incf
                       nponses (hash-table-count (the hash-table v))
                       pons-summary)
                      (very-unsafe-incf nsubs 1 pons-summary))
                     (t (very-unsafe-incf nponses (length v)
                                          pons-summary))))
                  tab))))))
    *memoize-info-ht*)
   (print-alist
    `((" Pons hits/calls"
       ,(let* ((c *pons-call-counter*)
               (d *pons-misses-counter*))
          (format nil "~,1e / ~,1e = ~,2f" d c (/ (- c d) (+ .0000001 c)))))
      (" Number of pons tables" ,(ofnum nponstab))
      (" Number of pons sub tables" ,(ofnum nsubs))
      (" Sum of pons sub table sizes" ,(ofnum sssub))
      (" Number of ponses" ,(ofnum nponses)))
    5)
   (oft ")")
   nil)))

(defun memoized-values (&optional (fn (memoized-functions)))

  "(MEMOIZED-VALUES fn) prints all the currently memoized values for
   FN."

  (cond ((listp fn) (mapc #'memoized-values fn))
        ((not (memoizedp-raw fn))
         (oft "~%; Memoized-values:  ~s is not memoized." fn))
        (t (let ((tb (symbol-value
                      (access memoize-info-ht-entry
                              (gethash fn *memoize-info-ht*)
                              :tablename))))
             (cond ((and tb (not (eql 0 (hash-table-count
                                         (the hash-table tb)))))
                    (oft "~%; Memoized values for ~s." fn)
                    (maphash (lambda (key v)
                               (format t "~%~s~%=>~%~s" key v))
                             (the hash-table tb)))))))
  nil)



(defn print-call-stack ()

  "(PRINT-CALL-STACK) prints the stack of memoized function calls
  currently running and the time they have been running."

  (let (l
        (time (internal-real-time))
        (*print-case* :downcase))
    (maphash (lambda (k v)
               (cond ((symbolp k)
                      (let ((x (symbol-value
                                (the symbol
                                  (access memoize-info-ht-entry
                                          v :start-time)))))
                        (declare (type mfixnum x))
                        (when (> x 0)
                          (push (cons k x) l))))))
             *memoize-info-ht*)
    (setq l (sort l #'< :key #'cdr))
    (setq l (loop for pair in l collect
                  (list (car pair)
                        (ofnum (/ (- time (cdr pair))
                                  *float-ticks/second*)))))
    (our-syntax-brief (when - (oft "~%? ~a" -)))
;; [Jared]: what?
;;    (our-syntax-brief
;;     (when (boundp '*acl2--*) (oft "~%> ~a~%" *acl2--*)))
    (when l
      (terpri)
      (print-alist
       (cons '("Stack of monitored function calls."
               "Time since outermost call.")
             l)
       5))))

(defun-one-output hons-calls (x)

  "For a memoized function fn, (HONS-CALLS fn) is the number of times
  fn has called hons."

  (setq x (coerce-index x))
  (aref *memoize-call-array*
        (the mfixnum
          (+ *ma-hons-index*
                       (the mfixnum
                         (* *2max-memoize-fns*
                            (the mfixnum x)))))))

(defun-one-output pons-calls (x)

  "For a memoized function X, (PONS-CALLS x) is the number of times
   X has called pons."

  (setq x (coerce-index x))
  (aref *memoize-call-array*
        (the mfixnum (+ *ma-pons-index*
                       (the mfixnum
                         (* *2max-memoize-fns*
                            (the mfixnum x)))))))

#+Clozure
(defun-one-output bytes-allocated (x)

  "For a memoized function X, (BYTES-ALLOCATED x) is the number of
  heap bytes X has caused to be allocated on the heap."

  (setq x (coerce-index x))
  (aref *memoize-call-array*
        (the mfixnum (+ *ma-bytes-index*
                       (the mfixnum
                         (* *2max-memoize-fns*
                            (the mfixnum x)))))))

(defun-one-output number-of-hits (x)

  "For a memoized function X, (NUMBER-OF-HITS x) is the number of
  times that a call of X returned a remembered answer."

  (setq x (coerce-index x))
  (aref *memoize-call-array*
        (the mfixnum (+ *ma-hits-index*
                       (the mfixnum
                         (* *2max-memoize-fns*
                            (the mfixnum x)))))))

(defun-one-output number-of-memoized-entries (x)

  "For a memoized function X, (NUMBER-OF-MEMOIZED-ENTRIES x) is the
  number of entries currently stored for X."

  (let ((h (gethash x *memoize-info-ht*)))
    (unless h (error "~a is not memoized." x))
    (let* ((sym (access memoize-info-ht-entry
                        h
                        :tablename))
           (val (symbol-value sym)))
      (if (hash-table-p val)
          (hash-table-count (the hash-table val))
        0))))

(defun-one-output number-of-mht-calls (x)

  "For a memoized function X, (NUMBER-OF-MHT-CALLS x) is the number
  of times that the memoize hash-table for X was created."

  (setq x (coerce-index x))
  (aref *memoize-call-array*
        (the mfixnum (+ *ma-mht-index*
                       (the mfixnum
                         (* *2max-memoize-fns*
                            (the mfixnum x)))))))

(defun-one-output time-for-non-hits/call (x)
  (setq x (coerce-index x))
  (let ((n (- (number-of-calls x) (number-of-hits x))))
    (if (zerop n) 0 (/ (total-time x) n))))

(defun-one-output time/call (x)
  (setq x (coerce-index x))
  (let ((n (number-of-calls x)))
    (if (zerop n) 0 (/ (total-time x) n))))

(defun-one-output hits/calls (x)
  (setq x (coerce-index x))
  (let ((n (number-of-calls x)))
    (if (zerop n) 0 (/ (number-of-hits x) (float n)))))

#+Clozure
(defun-one-output bytes-allocated/call (x)
  (setq x (coerce-index x))
  (let ((n (number-of-calls x)))
    (if (eql n 0)
        0
      (/ (bytes-allocated x) n))))

(defn char-list-fraction (l)
  (if (atom l) 0
    (+ (char-code (car l))
       (/ (char-list-fraction (cdr l))
          256))))

(defn symbol-name-order (s)

  "SYMBOL-NAME-ORDER maps symbols to rationals preserving
  lexicographic order."

  (unless (symbolp s) (setq s (fixnum-to-symbol s)))
  (- (char-list-fraction (coerce (symbol-name s) 'list))))

(defun-one-output execution-order (s)
  (unless (symbolp s) (setq s (fixnum-to-symbol s)))
  (the mfixnum (symbol-value
               (the symbol
                 (access memoize-info-ht-entry
                         (gethash s *memoize-info-ht*)
                         :start-time)))))



(defn compute-calls-and-times ()
  (let ((ma *memoize-call-array*)
        (2m *2max-memoize-fns*)
        (ca *compute-array*)
        (n (the fixnum (1+ *max-symbol-to-fixnum*))))
    (declare (type (simple-array mfixnum (*)) ma)
             (type (simple-array t (*)) ca)
             (type fixnum 2m n))
    (cond ((eql (length ca) n)
           (loop for i fixnum below n
                 do (setf (aref ca i) nil)))
          (t (setq *compute-array*
                   (make-array n :initial-element nil))
             (setq ca *compute-array*)))
    (loop for i fixnum below (the fixnum (* 2 n))
          do (setf (aref ma i) 0))
    (loop for i fixnum
          from *ma-initial-max-symbol-to-fixnum*
          to *max-symbol-to-fixnum* do
          (let ((2im (the fixnum (* i 2m))))
            (declare (type fixnum 2im))
            (loop for j fixnum
                  from *ma-initial-max-symbol-to-fixnum*
                  to *max-symbol-to-fixnum* do
                  (let* ((2j (the fixnum (* 2 j)))
                         (index (the fixnum (+ 2j 2im))))
                    (declare (type fixnum 2j index))
                    (let ((calls (the mfixnum (aref ma index))))
                      (declare (type mfixnum calls))
                      (when (> calls 0)
                        (let ((time (aref ma (the mfixnum
                                               (1+ index)))))
                          (declare (type mfixnum time))
                          (setf (aref ma 2j)
                                (the mfixnum (+ (aref ma 2j) calls)))
                          (setf (aref ma (the mfixnum (1+ 2j)))
                                (the mfixnum (+ (aref
                                                ma
                                                (the mfixnum (1+ 2j)))
                                               time)))
                          (push i (aref ca j))))))))))
  )

(defun-one-output number-of-calls (x)
  (setq x (coerce-index x))

; One must call COMPUTE-CALLS-AND-TIMES before invoking
; NUMBER-OF-CALLS to get sensible results.

  (aref *memoize-call-array*
        (the mfixnum (* 2 (the mfixnum x)))))

(defun-one-output print-not-called ()

  "(PRINT-NOT-CALLED) prints, one to a line, in alphabetic order, the
  currently memoized functions that have never been called.  Possibly
  useful when looking for test coverage."

  (compute-calls-and-times)
  (let ((ans nil))
    (maphash (lambda (k v)
               (declare (ignore v))
               (when (and (symbolp k)
                          (eql 0 (number-of-calls k)))
                 (push k ans)))
             *memoize-info-ht*)
    (loop for x in (sort ans 'alphorder)
          do (print x))))

(defun-one-output total-time (x)

  (setq x (coerce-index x))

; One must call COMPUTE-CALLS-AND-TIMES before invoking
; TOTAL-TIME to get sensible results.

  (/ (aref *memoize-call-array*
           (the fixnum (1+ (the fixnum (* 2 x)))))
     *float-ticks/second*))

(defn lex-> (l1 l2)
  (cond ((or (atom l1)
             (atom l2))
         nil)
        ((> (car l1) (car l2)) t)
        ((< (car l1) (car l2)) nil)
        (t (lex-> (cdr l1) (cdr l2)))))

(defun-one-output memoize-summary-sort ()
  (let (pairs)
    (maphash
     (lambda (fn v)
       (when (symbolp fn)
       (let ((num (access memoize-info-ht-entry v :num)))
         (declare (type fixnum num))
         (when (< 0 (number-of-calls num))
           (push (cons fn (loop for order
                                in *memoize-summary-order-list*
                                collect (funcall order fn)))
                 pairs)))))
     *memoize-info-ht*)
    (sort pairs
          (if *memoize-summary-order-reversed*
              (lambda (x y) (lex-> y x))
            #'lex->)
          :key #'cdr)))

(defun-one-output memoize-summary ()

  "(MEMOIZE-SUMMARY) reports data stored during the execution of the
  functions in (MEMOIZED-FUNCTIONS).

  Typically each call of a memoized function, fn, is counted.
  The elapsed time until an outermost function call of fn ends, the
  number of heap bytes allocated in that period (CCL only), and other
  'charges' are 'billed' to fn.  That is, quantities such as elapsed
  time and heap bytes allocated are not charged to subsidiary
  recursive calls of fn while an outermost call of fn is running.
  Recursive calls of fn, and memoized 'hits', are counted, unless fn
  was memoized with NIL as the value of the :INLINE parameter of
  MEMOIZE.

  The settings of the following determine, at the time a function is
  given to MEMOIZE, the information that is collected for calls of
  the function:

         Variable              type

         *RECORD-BYTES*       boolean    (available in CCL only)
         *RECORD-CALLS*       boolean
         *RECORD-HITS*        boolean
         *RECORD-HONS-CALLS*  boolean
         *RECORD-MHT-CALLS*   boolean
         *RECORD-PONS-CALLS*  boolean
         *RECORD-TIME*        boolean

  The settings of the following determine, at the time that
  MEMOIZE-SUMMARY is called, what information is printed:

         *REPORT-BYTES*       boolean   (available in CCL only)
         *REPORT-CALLS*       boolean
         *REPORT-CALLS-FROM*  boolean
         *REPORT-CALLS-TO*    boolean
         *REPORT-HITS*        boolean
         *REPORT-HONS-CALLS*  boolean
         *REPORT-MHT-CALLS*   boolean
         *REPORT-PONS-CALLS*  boolean
         *REPORT-TIME*        boolean

         *REPORT-ON-MEMO-TABLES*   boolean
         *REPORT-ON-PONS-TABLES*   boolean
         *MEMOIZE-SUMMARY-LIMIT*            (or integerp null)
         *MEMOIZE-SUMMARY-ORDER-LIST*       (symbol symbol ... symbol)
         *MEMOIZE-SUMMARY-ORDER-REVERSED*   boolean

  Functions are sorted lexicographically according to the ordering
  induced by the function names in *MEMOIZE-SUMMARY-ORDER-LIST*, each
  member of which must be a unary function that returns a rational.

  (CLEAR-MEMOIZE-TABLES) forgets the remembered values of all memoized
  function calls.  It does not alter a function's status as being a
  memoized function, nor does not it the monitoring data accumulated.

  (UNMEMOIZE-ALL) undoes the memoization status of all memoized
  functions.

  (CLEAR-MEMOIZE-CALL-ARRAY) zeroes out the monitoring information for
  all functions.  It does not alter any function's status as a
  memoized function nor does it change the values remembered for any
  memoized function.

  Here is an example of hacking with *MEMOIZE-SUMMARY-ORDER-LIST* that
  instructs MEMOIZE-SUMMARY to print information about, say,
  1ST-MOD-ERR first:

    (PUSH (LAMBDA (FN)
            (IF (EQ FN '1ST-MOD-ERR) 1 0))
          *MEMOIZE-SUMMARY-ORDER-LIST*)."

  (compute-calls-and-times)
  (memoize-summary-after-compute-calls-and-times)
  nil)

(defg *short-symbol-name-width* 30)

(defn short-symbol-name (sym)
  (let ((str (symbol-name sym)))
    (cond ((> (length str) *short-symbol-name-width*)
           (intern (format nil "~a..."
                           (subseq str 0
                                   *short-symbol-name-width*))
                   (symbol-package sym)))
          (t sym))))

(defun-one-output outside-p (x)
  (or (<= x *ma-initial-max-symbol-to-fixnum*)
      (null (gethash x *memoize-info-ht*))))

(defun-one-output memoize-summary-after-compute-calls-and-times ()

;  If COMPUTE-CALLS-AND-TIMES is not called shortly before this
;  function, MEMOIZE-SUMMARY-AFTER-COMPUTE-CALLS-AND-TIMES, is called,
;  the information reported may be quite untimely.

 (let* ((fn-pairs (memoize-summary-sort))
        (ma *memoize-call-array*)
        (len-orig-fn-pairs (len fn-pairs))
        (len-fn-pairs 0)
        (global-total-time 0)
        #+Clozure
        (global-bytes-allocated 0)
        (global-hons-calls 0)
        (global-pons-calls 0))
   (declare (type (simple-array mfixnum (*)) ma)
            (type fixnum len-orig-fn-pairs len-fn-pairs))
   (when (and *memoize-summary-limit*
              (> len-orig-fn-pairs *memoize-summary-limit*))
     (setq fn-pairs
           (loop for i fixnum from 1 to *memoize-summary-limit* as
                 x in fn-pairs collect x)))
   (setq len-fn-pairs (len fn-pairs))
   (when (> len-fn-pairs 0)
     (oft "~%Sorted by *memoize-summary-order-list* = ~a."
          *memoize-summary-order-list*)
     (when (< len-fn-pairs len-orig-fn-pairs)
       (oft "~%Reporting on ~:d of ~:d functions because ~
             *memoize-summary-limit* = ~a."
            len-fn-pairs
            len-orig-fn-pairs
            *memoize-summary-limit*)))
   (setq global-total-time
     (loop for pair in fn-pairs sum (total-time (car pair))))
   #+Clozure
   (setq global-bytes-allocated
     (+ 1 (loop for pair in fn-pairs sum
                (bytes-allocated (car pair)))))
   (setq global-hons-calls
     (+ 1 (loop for pair in fn-pairs sum (hons-calls (car pair)))))
   (setq global-pons-calls
     (+ 1 (loop for pair in fn-pairs sum (pons-calls (car pair)))))
   (when (null fn-pairs)
     (oft "~%(memoize-summary) has nothing to report.~%"))
   (loop for pair in fn-pairs do
    (let* ((fn (car pair))
           (l (gethash fn *memoize-info-ht*))
           (tablename
            (symbol-value
             (access memoize-info-ht-entry l :tablename)))
           (ponstablename
            (symbol-value
             (access memoize-info-ht-entry l :ponstablename)))
           (start-time
            (the mfixnum
              (symbol-value
               (the symbol
                 (access memoize-info-ht-entry l :start-time)))))
           (num (the fixnum (access memoize-info-ht-entry l :num)))
           (nhits (the mfixnum (number-of-hits num)))
           (nmht (the mfixnum (number-of-mht-calls num)))
           (ncalls
            (the mfixnum (max 1 (the mfixnum (number-of-calls num)))))
           (hons-calls (the mfixnum (hons-calls num)))
           (pons-calls (the mfixnum (pons-calls num)))
           (no-hits (or (not *report-hits*)
                        (null (memoize-condition fn))))
           #+Clozure
           (bytes-allocated (bytes-allocated num))
           (tt (max .000001 (total-time num)))
           (t/c (time/call num))
           (tnh (time-for-non-hits/call num))
           (in-progress-str
            (if (eql start-time -1) " " ", running, "))
           (selftime tt))
      (declare (type integer start-time)
               (type fixnum num)
               (type mfixnum nhits nmht ncalls
                     hons-calls pons-calls
                     #+Clozure bytes-allocated))
      (print-alist
       `((,(format nil "(defun ~s~a~a"
                   (short-symbol-name fn)
                   (if no-hits
                       (ofn " call~a" (if (eql nhits 1) "" "s"))
                     " hits/calls")
                   in-progress-str)
          ,(if (or *report-calls* *report-hits*)
               (if no-hits
                   (format nil "~a" (ofnum ncalls))
                 (format nil "~8,2e/~8,2e = ~4,1f%"
                         nhits
                         ncalls
                         (* 100 (/ nhits (float ncalls)))))
             ""))
         ,@(if (and *report-mht-calls* (>= nmht 2))
               `((" Number of calls to mht" ,(ofnum nmht))))
         ,@(if *report-time*
               `((" Time of all outermost calls"
                  ,(format nil "~a; ~4,1f%"
                           (ofnum tt)
                           (* 100 (/ tt global-total-time))))
                 (" Time per call" ,(ofnum t/c))))

         ,@(if (let ((v (gethash fn *memoize-info-ht*)))
                 (and (null (access memoize-info-ht-entry v
                                    :condition))
                      (null (access memoize-info-ht-entry v
                                    :inline))
                      (< t/c 1e-6)))
               `((,(format nil " Doubtful timing info for ~a." fn)
                  "Heisenberg effect.")))
         #+Clozure
         ,@(if (and (> bytes-allocated 0) *report-bytes*)
               `((" Heap bytes allocated"
                  ,(format nil "~a; ~4,1f%"
                           (ofnum bytes-allocated)
                           (* 100 (/ bytes-allocated
                                     global-bytes-allocated))))
                 (" Heap bytes allocated per call"
                  ,(ofnum (/ bytes-allocated ncalls)))))
         ,@(if (and (> hons-calls 0) (> global-hons-calls 0)
                    *report-hons-calls*)
               `((" Hons calls"
                  ,(format nil "~a; ~4,1f%"
                           (ofnum hons-calls)
                           (* 100 (/ hons-calls global-hons-calls))))))
         ,@(if (and (> pons-calls 0)
                    (> global-pons-calls 0)
                    *report-pons-calls*)
               `((" Pons calls"
                  ,(format nil "~a; ~4,1f%"
                           (ofnum pons-calls)
                           (* 100 (/ pons-calls global-pons-calls))))))
         ,@(if (and *report-hits* *report-time* (not (eql 0 nhits)))
               `((" Time per missed call" ,(ofnum tnh))))
         ,@(if *report-calls-to*
               (let ((l nil)
                     (outside-fn-time 0)
                     (outside-fn-count 0))
                 (declare (type mfixnum outside-fn-count))
                 (loop for callern in
                  (loop for i below (length *compute-array*)
                        when (member num (aref *compute-array* i))
                        collect i) do
                  (let* ((call-loc
                          (the fixnum
                            (+ (* 2 callern)
                               (the fixnum
                                 (* num *2max-memoize-fns*)))))
                         (calls (aref ma call-loc)))
                    (declare (fixnum call-loc)
                             (type mfixnum calls))
                    (let* ((time-loc (the fixnum (1+ call-loc)))
                           (time (aref ma time-loc))
                           (ltt (/ time *float-ticks/second*)))
                      (decf selftime ltt)
                      (cond ((or (outside-p callern)
                                 (< (* 100 ltt) tt))
                             (incf outside-fn-time ltt)
                             (incf outside-fn-count calls))
                            (t (push
                                `((,(format nil " To ~a"
                                            (fixnum-to-symbol callern))
                                   ,(format nil
                                     "~8,2e calls took~8,2e;~5,1f%"
                                     calls ltt
                                     (if (> (* 10000 ltt) tt)
                                         (* 100 (/ ltt tt))
                                       '?)))
                                  . ,(if *sort-to-from-by-calls*
                                         calls
                                       time))
                                l))))))
                 (when (> outside-fn-time 0)
                   (push
                    `((,(format nil " To other functions")
                       ,(format nil "~8,2e calls took~8,2e;~5,1f%"
                                outside-fn-count
                                outside-fn-time
                                (if (> (* 10000 outside-fn-time) tt)
                                    (* 100 (/ outside-fn-time tt))
                                  '?)))
                      . ,(if *sort-to-from-by-calls*
                             outside-fn-count
                           outside-fn-time))
                    l))
                 (when (and (> selftime 0)
                            (not (= selftime tt)))
                   (push `((,(ofn " To self/unprofiled functions")
                            ,(ofn "~8,2e;~5,1f%"
                                  selftime
                                  (if (> (* 10000 selftime) tt)
                                      (* 100 (/ selftime tt))
                                    '?)))
                           . ,(if *sort-to-from-by-calls*
                                  0 ;; ?
                                (* selftime *float-ticks/second*)))
                         l))
                 (setq l (sort l #'> :key #'cdr))
                 ; (cw "l: ~x0~%" l)
                 (strip-cars l)))
         ,@(if *report-calls-from*
               (let ((l nil)
                     (2num (the fixnum (* 2 num)))
                     (outside-caller-time 0)
                     (outside-caller-count 0))
                 (declare (fixnum 2num))
                 (loop
                  for callern in (aref *compute-array* num) do
                  (let* ((call-loc
                          (the fixnum
                            (+ 2num
                               (the fixnum
                                 (* callern *2max-memoize-fns*)))))
                         (calls (aref ma call-loc)))
                    (declare (fixnum call-loc)
                             (type mfixnum calls))
                    (let* ((time-loc (the fixnum (1+ call-loc)))
                           (time (aref ma time-loc))
                           (ltt (/ time *float-ticks/second*)))
                      (cond
                       ((or (outside-p callern) (< (* 100 ltt) tt))
                        (incf outside-caller-time ltt)
                        (incf outside-caller-count calls))
                       (t (push
                           `((,(ofn " From ~a"
                                    (fixnum-to-symbol callern))
                              ,(ofn "~8,2e calls took~8,2e;~5,1f%"
                                    calls
                                    ltt
                                    (if (< .001 ltt tt)
                                        (* 100 (/ ltt tt))
                                      '?)))
                             . ,(if *sort-to-from-by-calls*
                                    calls
                                  time))
                           l))))))
                 (when (> outside-caller-time 0)
                   (push
                    `((,(ofn " From other functions")
                       ,(ofn "~8,2e calls took~8,2e;~5,1f%"
                             outside-caller-count
                             outside-caller-time
                             (if (< .001 outside-caller-time tt)
                                 (* 100 (/ outside-caller-time tt))
                               '?)))
                      . ,(if *sort-to-from-by-calls*
                             outside-caller-count
                           outside-caller-time))
                    l))
                 (setq l (sort l #'> :key #'cdr))
                 (strip-cars l)))
             .
         ,(if (and (not *report-on-memo-tables*)
                   (not *report-on-pons-tables*))
              nil
            (let ((spsub 0) (nponses 0) (npsubs 0))
              (declare (type mfixnum spsub nponses npsubs))
              (and
               (and ponstablename *report-on-pons-tables*)
               (maphash
                (lambda (key value)
                  (declare (ignore key))
                  (cond
                   ((not (listp value))
                    (very-unsafe-incf spsub (hash-table-size
                                             (the hash-table value))
                                      memoize-summary)
                    (very-unsafe-incf nponses
                                      (hash-table-count
                                       (the hash-table value))
                                      memoize-summary)
                    (very-unsafe-incf npsubs 1 memoize-summary))
                   (t (very-unsafe-incf nponses
                                        (length value)
                                        memoize-summary))))
                ponstablename))
              `(,@(and
                   (and tablename *report-on-memo-tables*)
                   `((,(ofn " Memoize table count/size")
                      ,(ofn "~8,2e/~8,2e = ~4,1f%"
                            (hash-table-count
                             (the hash-table tablename))
                            (hash-table-size
                             (the hash-table tablename))
                            (* 100
                               (/ (hash-table-count
                                   (the hash-table tablename))
                                  (hash-table-size
                                   (the hash-table tablename))))))))
                  ,@(and
                     (and ponstablename *report-on-pons-tables*)
                     `((" (Pons table count/size"
                        ,(ofn "~:d/~:d = ~4,1f%)"
                              (hash-table-count
                               (the hash-table ponstablename))
                              (hash-table-size
                               (the hash-table ponstablename))
                              (* 100
                                 (/ (hash-table-count
                                     (the hash-table ponstablename))
                                    (hash-table-size
                                     (the hash-table
                                       ponstablename))))))
                       (" (Number of pons sub tables"
                        ,(ofn "~a)" (ofnum npsubs)))
                       (" (Sum of pons sub table sizes"
                        ,(ofn "~a)" (ofnum spsub)))
                       (" (Number of ponses"
                        ,(ofn "~a)" (ofnum nponses)))))))))
       5))
         (oft ")"))))


(defun-one-output empty-ht-p (x)
  (and (hash-table-p x)
       (eql 0 (hash-table-count (the hash-table x)))))

(defn clear-one-memo-and-pons-hash (l)

;  It is debatable whether one should use the CLRHASH approach or
;  the set-to-NIL approach in CLEAR-ONE-MEMO-AND-PONS-HASH.  The
;  CLRHASH approach, in addition to reducing the number of
;  MAKE-HASH-TABLE calls necessary, has the effect of immediately
;  clearing a hash-table even if some other function is holding on
;  to it, so more garbage may get garbage collected sooner than
;  otherwise.  The set-to-NIL approach has the advantage of costing
;  very few instructions and very little paging.

  (let* ((fn (access memoize-info-ht-entry l :fn))
         (mt (symbol-value (access memoize-info-ht-entry l :tablename)))
         (pt (symbol-value (access memoize-info-ht-entry l :ponstablename)))
         (mt-count (and mt (hash-table-count mt)))
         (pt-count (and pt (hash-table-count pt))))
    (when mt
      (setf (symbol-value (access memoize-info-ht-entry l :tablename)) nil))
    (when pt
      (setf (symbol-value (access memoize-info-ht-entry l :ponstablename)) nil))
    (when (or mt-count pt-count)
      (update-memo-max-sizes fn (or pt-count 1) (or mt-count 1)))
    nil))

(defun-one-output clear-memoize-table (k)

; See also hons.lisp.

  (when (symbolp k)
    (let ((l (gethash k *memoize-info-ht*)))
      (when l (clear-one-memo-and-pons-hash l))))
  k)

(defun-one-output clear-memoize-tables ()

; See hons.lisp.

  (let (success)
    (unwind-protect
        (progn
          (maphash (lambda (k l)
                     (when (symbolp k)
                       (clear-one-memo-and-pons-hash l)))
                   *memoize-info-ht*)
          (setq success t))
      (or success (error "clear-memoize-tables failed."))))
  nil)

(defn clear-memoize-call-array ()

  "(CLEAR-MEMOIZE-CALL-ARRAY) zeros out all records of function calls
  as far as reporting by MEMOIZE-SUMMARY, etc. is concerned."

  (let ((m *memoize-call-array*))
    (declare (type (simple-array mfixnum (*)) m))
    (loop for i fixnum below (length m)
          do (setf (aref m i) 0))))

(defn clear-memoize-statistics ()
  (clear-memoize-call-array)
  nil)


(defun-one-output memoize-init ()

  (when *memoize-init-done*
    ;; Already done
    (return-from memoize-init nil))

  (unless (eql *caller* (the fixnum
                          (* *ma-initial-max-symbol-to-fixnum*
                             *2max-memoize-fns*)))
    (error "memoize-init:  A memoized function is running."))

  (let (success)
    (unwind-protect
        (progn
          (setq *pons-call-counter* 0)
          (setq *pons-misses-counter* 0)
          (setq *memoize-info-ht* (hl-mht))
          (setf (gethash *ma-initial-max-symbol-to-fixnum*
                         *memoize-info-ht*)
                "outside-caller")
          (setq *max-symbol-to-fixnum*
                *ma-initial-max-symbol-to-fixnum*)
          (setq *2max-memoize-fns*
                (* 2 *initial-max-memoize-fns*))
          (sync-memoize-call-array)
          (setq success t))
      (if success
          (setq *memoize-init-done* t)
        (error "memoize-init failed."))))

   nil)



;; [Jared and Sol]: It is gross to leave these in here, but we're going to do
;; it, because right now they're used within WATCH.  If we eventually decide
;; that WATCH is deprecated or anything like that, we can move these to
;; centaur/misc/memory-mgmt, where they are actually used now.

(defg *max-mem-usage* (expt 2 32)

  "*MAX-MEM-USAGE* an upper bound, in bytes of memory used, that when
  exceeded results in certain garbage collection actions.

  Note: not used by ACL2(h) itself; see the centaur/misc/memory-mgmt
  books.")

(defg *gc-min-threshold* (expt 2 30)
  "Note: not used by ACL2(h) itself; see the centaur/misc/memory-mgmt
  books.")




#+Clozure
(defun-one-output set-gc-threshold (bound)
  ;; bozo used?
  (when (< (ccl::lisp-heap-gc-threshold) bound)
    (ccl::set-lisp-heap-gc-threshold bound)
    (ccl::use-lisp-heap-gc-threshold))
  nil)


#+Clozure
(defmacro globlet (bindings &rest rest)
  ;; [Jared]: this is only used in with-lower-overhead AFAICT.

  "GLOBLET is reminiscent of LET.  It is intended to be used in CCL
  with variables that are introduced via DEFG or DEFV, i.e., may not
  be LET or LAMBDA bound.  UNWIND-PROTECT is used to try to make sure
  that the old value, which is assumed to exist, is restored."

  (unless
      (and (symbol-alistp bindings)
           (loop for pair in bindings always
                 (let ((var (car pair))
                       (d (cdr pair)))
                   (and (consp d)
                        (null (cdr d))
                        (not (constantp var))))))
    (error "GLOBLET: ** bad bindings ~a." bindings))
  (let ((vars (loop for b in bindings collect
                    (make-symbol (symbol-name (car b))))))
    `(let ,(loop for b in bindings as v in vars collect
                  (list v (car b)))
          (unwind-protect
              (progn (psetq
                      ,@(loop for b in bindings nconc
                              (list (car b) (cadr b))))
                     ,@rest)
            (psetq ,@(loop for b in bindings as v in vars nconc
                           (list (car b) v)))))))

#-Clozure
(defmacro globlet (&rest r)

; See #+Clozure definition for an explanation of why we need this macro.  In
; Lispworks, we get this warning if we use the #+Clozure definition:

; ;;;*** Warning in ACL2::HONS-INIT-HOOK-MEMOIZATIONS: #:*COUNT-PONS-CALLS* bound lexically.

; So we use a much simpler definition here.

  `(let ,@r))

(defmacro with-lower-overhead (&rest r)
  `(let ((*record-bytes* nil)
         (*record-calls*

; It is a mystery why we need to set *record-calls* to t in LispWorks.  But we
; do.  Otherwise, for example, evaluation hangs for (bad-lisp-objectp
; (make-list 100000)) when bad-lisp-objectp is in the initial memoized state
; produced by calling acl2h-init (see acl2h-init-memoizations)

          #-lispworks nil #+lispworks t)
         (*record-hits* nil)
         (*record-hons-calls* nil)
         (*record-mht-calls* nil)
         (*record-pons-calls* nil)
         (*record-time* nil))
     (globlet ((*count-pons-calls* nil))
              ,@ r)))


; [Jared]: this acl2h-init-memoizations stuff is almost certainly broken in
; some sense.  Why unmemoize/rememoize exactly these functions?  The answer is
; probably: it works for using ACL2(p) in most books, where no other
; memoization has taken place.  But this is just an accident.  Really ACL2(p)
; needs a way to turn off memoization globally for awhile, unless we're going
; going to get to a point where memoization is thread-safe.

(defun acl2h-init-memoizations ()

; Keep in sync with acl2h-init-unmemoizations.

; We pull out the memoization calls so we can unmemoize and re-memoize these
; functions when the user enables and disables waterfall parallelism,
; respectively.

  (when (not (memoizedp-raw 'bad-lisp-objectp))
    (with-lower-overhead
     (memoize-fn 'bad-lisp-objectp :forget t)))

  (when (not (memoizedp-raw 'worse-than-builtin))
    ;; Warning: If this is changed or removed, visit the comment in
    ;; worse-than-builtin.
    (with-lower-overhead
     (memoize-fn 'worse-than-builtin
                 :condition ; Sol Swords suggestion
                 '(and (nvariablep term1)
                       (not (fquotep term1))
                       (nvariablep term2)
                       (not (fquotep term2))))))

  (when (not (memoizedp-raw 'fchecksum-obj))
    ;; Warning: If this memoization is removed, modify the comment in
    ;; fchecksum-obj about memoization of that function.
    (with-lower-overhead
     (memoize-fn 'fchecksum-obj :forget t)))

  (when (not (memoizedp-raw 'expansion-alist-pkg-names-memoize))
    ;; Warning: If this memoization is removed, modify the comment in
    ;; expansion-alist-pkg-names about memoization of that function.
    (with-lower-overhead
     (memoize-fn 'expansion-alist-pkg-names-memoize :forget t)))

  )

(defun acl2h-init-unmemoizations ()

; Keep in sync with acl2h-init-memoizations.

; We avoid unmemoizing functions when their memoization does not interfere with
; waterfall parallelism.  We formerly also unmemoized here the functions
; fchecksum-obj and expansion-alist-pkg-names-memoize, with the result that
; certification of community book books/system/doc/render-doc-combined with
; ACL2(hp) went out to lunch (specifically, it seemed looking at a backtrace,
; because of fchecksum-obj).

; We avoid memoizing bad-lisp-objectp because the *1* function for
; symbol-package-name calls chk-bad-lisp-object, and of course
; symbol-package-name can be called during the waterfall.

  (when (memoizedp-raw 'bad-lisp-objectp)
    (unmemoize-fn 'bad-lisp-objectp))
  (when (memoizedp-raw 'worse-than-builtin)
    (unmemoize-fn 'worse-than-builtin)))

;;;;;;;;;;
;;; Start memory management code (start-sol-gc)
;;;;;;;;;;

; This section of code was suggested by Jared Davis as a way to regain
; performance of ACL2(h) on regressions at UT CS.  Initially, these regressions
; shows significant slowdown upon including new memoization code from Centaur
; on 3/28/2013:
; ; old:
; 24338.570u 1357.200s 1:19:02.75 541.7%	0+0k 0+1918864io 0pf+0w
; ; new:
; 33931.460u 1017.070s 1:43:24.28 563.2%	0+0k 392+1931656io 0pf+0w
; After restoring (start-sol-gc) in function acl2h-init, we regained the old
; level of performance for a UT CS ACL2(h) regression, with the new memoizaion
; code.

(defun looking-at (str1 str2 &key (start1 0) (start2 0))

;  (LOOKING-AT str1 str2 :start1 s1 :start2 s2) is non-NIL if and only
;  if string STR1, from location S1 to its end, is an initial segment
;  of string STR2, from location S2 to its end.

   (unless (typep str1 'simple-base-string)
     (error "looking at:  ~a is not a string." str1))
   (unless (typep str2 'simple-base-string)
     (error "looking at:  ~a is not a string." str2))
   (unless (typep start1 'fixnum)
     (error "looking at:  ~a is not a fixnum." start1))
   (unless (typep start2 'fixnum)
     (error "looking at:  ~a is not a fixnum." start2))
   (locally
     (declare (simple-base-string str1 str2)
              (fixnum start1 start2))
     (let ((l1 (length str1)) (l2 (length str2)))
       (declare (fixnum l1 l2))
       (loop
        (when (>= start1 l1) (return t))
        (when (or (>= start2 l2)
                  (not (eql (char str1 start1)
                            (char str2 start2))))
          (return nil))
        (incf start1)
        (incf start2)))))

(defun meminfo (pat)

;  General comment about PROBE-FILE.  PROBE-FILE, according to Gary
;  Byers, may reasonably cause an error.  He is undoubtedly right.  In
;  such cases, however, Boyer generally thinks and wishes that it
;  returned NIL, and generally, therefore, ensconces a PROBE-FILE
;  within an IGNORE-ERROR in his code.

  (or
   (and
    (our-ignore-errors (probe-file "/proc/meminfo"))
    (with-standard-io-syntax

; Note for GCL:
; As of late May 2013, with-standard-io-syntax seems to work properly in ANSI
; GCL.  If necessary one could use our-with-standard-io-syntax here, but better
; would be to use an up-to-date ANSI GCL.

     (with-open-file (stream "/proc/meminfo")
                     (let (line)
                       (loop while (setq line (read-line stream nil nil)) do
                             (when (looking-at pat line)
                               (return
                                (values
                                 (read-from-string line nil nil
                                                   :start (length pat))))))))))
   0))

(let ((physical-memory-cached-answer nil))
   (defun physical-memory ()
     (or physical-memory-cached-answer
         (setq physical-memory-cached-answer
               (meminfo "MemTotal:")))))


(defvar *sol-gc-installed* nil)


#+Clozure
(defun set-and-reset-gc-thresholds ()
   (let ((n (max (- *max-mem-usage* (ccl::%usedbytes))
                 *gc-min-threshold*)))
     (cond ((not (eql n (ccl::lisp-heap-gc-threshold)))
            (ccl::set-lisp-heap-gc-threshold n)
;; Commented out since ofvv no longer is defined:
;            (ofvv "~&; set-and-reset-gc-thresholds: Reserving ~:d additional bytes.~%"
;                  n)
            )))
   (ccl::use-lisp-heap-gc-threshold)
; (ofvv "~&; set-and-reset-gc-thresholds: Calling ~
;        ~%(use-lisp-heap-gc-threshold).")
   (cond ((not (eql *gc-min-threshold*
                    (ccl::lisp-heap-gc-threshold)))
          (ccl::set-lisp-heap-gc-threshold *gc-min-threshold*)
;; Commented out since ofvv no longer is defined:
;          (ofvv "~&; set-and-reset-gc-thresholds: Will reserve ~:d bytes after
;next GC.~%"
;                *gc-min-threshold*)
          )))


#+Clozure
(defun start-sol-gc ()

;          Sol Sword's scheme to control GC in CCL
;
; The goal is to get CCL to perform a GC whenever we're using almost
; all the physical memory, but not otherwise.
;
; The usual way of controlling GC on CCL is via LISP-HEAP-GC-THRESHOLD.
; This value is approximately amount of memory that will be allocated
; immediately after GC.  This means that the next GC will occur after
; LISP-HEAP-GC-THRESHOLD more bytes are used (by consing or array
; allocation or whatever.)  But this means the total memory used by the
; time the next GC comes around is the threshold plus the amount that
; remained in use at the end of the previous GC.  This is a problem
; because of the following scenario:
;
;  - We set the LISP-HEAP-GC-THRESHOLD to 3GB since we'd like to be able
;    to use most of the 4GB physical memory available.
;
;  - A GC runs or we say USE-LISP-HEAP-GC-THRESHOLD to ensure that 3GB
;    is available to us.
;
;  - We run a computation until we've exhausted this 3GB, at which point
;    a GC occurs.
;
;  - The GC reclaims 1.2 GB out of the 3GB used, so there is 1.8 GB
;    still in use.
;
;  - After GC, 3GB more is automatically allocated -- but this means we
;    won't GC again until we have 4.8 GB in use, meaning we've gone to
;    swap.
;
; What we really want is, instead of allocating a constant additional
; amount after each GC, to allocate up to a fixed total amount including
; what's already in use.  To emulate that behavior, we use the hack
; below.  This operates as follows (assuming the same 4GB total physical
; memory as in the above example:)
;
; 1. We set the LISP-HEAP-GC-THRESHOLD to (3.5G - used bytes) and call
; USE-LISP-HEAP-GC-THRESHOLD so that our next GC will occur when we've
; used a total of 3.5G.
;
; 2. We set the threshold back to 1GB without calling
; USE-LISP-HEAP-GC-THRESHOLD.
;
; 3. Run a computation until we use up the 3.5G and the GC is called.
; Say the GC reclaims 1.2GB so there's 2.3GB in use.  1GB more (the
; current LISP-HEAP-GC-THRESHOLD) is allocated so the ceiling is 3.3GB.)
;
; 4. A post-GC hook runs which again sets the threshold to (3.5G -
; used bytes), calls USE-LISP-HEAP-GC-THRESHOLD to raise the ceiling to
; 3.5G, then sets the threshold back to 1GB, and the process repeats.
;
; A subtlety about this scheme is that post-GC hooks runs in a separate
; thread from the main execution.  A possible bug is that in step 4,
; between checking the amount of memory in use and calling
; USE-LISP-HEAP-GC-THRESHOLD, more memory might be used up by the main
; execution, which would set the ceiling higher than we intended.  To
; prevent this, we interrupt the main thread to run step 4.


; The following settings are highly heuristic.  We arrange that gc
; occurs at 1/8 of the physical memory size in bytes, in order to
; leave room for the gc point to grow (as per
; set-and-reset-gc-thresholds).  If we can determine the physical
; memory; great; otherwise we assume that it it contains at least 4GB,
; a reasonable assumption we think for anyone using the HONS version
; of ACL2.

   (let* ((phys (physical-memory))
          (memsize (cond ((> phys 0) (* phys 1024)) ; to bytes
                         (t (expt 2 32)))))
     (setq *max-mem-usage* (min (floor memsize 8)
                                (expt 2 31)))
     (setq *gc-min-threshold* (floor *max-mem-usage* 4)))

; OLD COMMENT:
; Trigger GC after we've used all but (1/8, but not more than 1 GB) of
; the physical memory.

   (unless *sol-gc-installed*
     (ccl::add-gc-hook
      #'(lambda ()
          (ccl::process-interrupt
           (slot-value ccl:*application* 'ccl::initial-listener-process)
           #'set-and-reset-gc-thresholds))
      :post-gc)
     (setq *sol-gc-installed* t))

   (set-and-reset-gc-thresholds))

;;;;;;;;;;
;;; End of memory management code (start-sol-gc)
;;;;;;;;;;

(defun-one-output acl2h-init ()

; We assume ACL2-DEFAULT-RESTART will be called at least once.  We suspect it
; will be called whenever an ACL2H CCL saved image is started up.  We know that
; ACL2-DEFAULT-RESTART calls ACL2H-INIT.  We are unsure how many times
; ACL2-DEFAULT-RESTART might be called, and so we code ACL2H-INIT so that it
; may be called multiple times.

  ;; [Jared]: if this in-package matters, I don't understand anything.
  ;; (in-package "ACL2")

  (memoize-init)
  (float-ticks/second-init)

  ;; [Jared]: Not sure whether we care about this anymore.  With serialize
  ;; we probably do not.  It might be best NOT to mess with this to
  ;; minimize differences between ACL2 and ACL2(h).  Trying to remove it.
  ;; "If the ACL2 global PRINT-CIRCLE is not t, then .cert files may be huge."
  ;; (f-put-global 'print-circle t *the-live-state*)
  ;; (f-put-global 'print-circle-files t *the-live-state*)

  #+static-hons
  ;; [Jared]: With *print-array* turned on, we end up sometimes seeing the
  ;; SBITS array in backtraces, etc, which can effectively kill your session
  ;; (can't interrupt, etc.).  This is only a problem with static-honsing since
  ;; classic honsing doesn't have sbits anyway.
  (setq *print-array* nil)

  ;; [Jared]: why do we do this?  presumably it affects raw lisp.  should this
  ;; be anything we care about?  Maybe ACL2 should set this instead of ACL2(h).
  (setq *print-pretty* t)

  ;; The following is restored after including mods from Jared Davis,
  ;; 3/29/2013.  See comment "Start memory management code (start-sol-gc)".
  #+Clozure
  (start-sol-gc)

  (acl2h-init-memoizations)

  #+Clozure
  (progn

    ;; [Jared]: Is there any reason to care about site names?  I'm going
    ;; to remove these for now.
    ;; (setq ccl::*long-site-name*
    ;;                     (ignore-errors (ccl::getenv "HOSTNAME")))
    ;; (setq ccl::*short-site-name*
    ;;   (subseq ccl::*long-site-name*
    ;;           0 (search "." ccl::*long-site-name*)))


    ;; [Jared]: Is there any reason to mess with this?  The
    ;; *print-right-margin* is a CLHS thing, not CCL-specific, so why it
    ;; this in #+Clozure?  How about we don't mess with it.
    ;; (setq *print-right-margin*
    ;;  (ignore-errors (read-from-string (ccl::getenv "COLUMNS"))))


    "Permit FUNCTION-LAMBDA-EXPRESSION to return the form used in the DEFUN of
     a function symbol."
    ;; [Jared]: How many of these are actually needed for FLE to work?  Which
    ;; of them do we actually want?  See also comments in acl2.lisp, "Some
    ;; hacks for CCL", where these settings used to be getting redundantly set.
    ;; What do these do?
    (setq ccl::*save-definitions* t)
    (setq ccl::*save-source-locations*
          ;; This contradicts setting in acl2.lisp; do we need it?
          t)
    (setq ccl::*fasl-save-definitions* t)
    (setq ccl::*record-source-file*    t)


    "Allow control-d to exit from CCL."
    ;; [Jared]: This is useful, but, shouldn't it be part of just ordinary ACL2
    ;; instead of ACL2(h), though?  Or shouldn't we have it as part of our
    ;; lisp-config file, if we ever implement that sort of thing?
    (setq ccl::*quit-on-eof* t)


    "It is usually best for the user to know what the garbage collector is
     doing when using HONS and MEMOIZE."
    ;; [Jared]: This sets full-gc messages on but leaves EGC messages off.
    ;; We're disabling EGC anyway, but when we've experimented with leaving it
    ;; on, the EGC messages are way too verbose.
    (ccl::gc-verbose t nil)

    ;; [Jared]: we turn off EGC because it doesn't seem to work well with
    ;; memoizing worse-than-builtin and sometimes seems buggy; but we want to
    ;; investigate this more.
    (ccl::egc nil))

  nil)



;;; SHORTER, OLDER NAMES

; Note: memsum is defined in memoize.lisp.

(defun memstat (&rest r)
  (apply #'memoized-values r))

(defmacro memo-on (&rest r)
  `(memoize-on ,@r))

(defmacro memo-off (&rest r)
  `(memoize-off ,@r))

(defun clear-memo-tables (&rest r)
  (setq *pons-call-counter* 0)
  (setq *pons-misses-counter* 0)
  (apply #'clear-memoize-tables r))



(defn lower-overhead ()
  ;; Doesn't help much.
  (setq *record-bytes* nil)
  (setq *record-calls*

; See the comment about LispWorks in with-lower-overhead; we make the analogous
; adjustment for LispWorks here, in case it's necessary.

        #-lispworks nil #+lispworks t)
  (setq *record-hits* nil)
  (setq *record-hons-calls* nil)
  (setq *record-mht-calls* nil)
  (setq *record-pons-calls* nil)
  (setq *record-time* nil)
  (setq *count-pons-calls* nil))

#+Clozure
(defun our-gctime ()
  (ccl::timeval->microseconds ccl::*total-gc-microseconds*))

(defun update-memo-entry-for-attachments (fns entry wrld)

; We return (mv changed-p new-entry), where if changed-p is not t or nil then
; it is a function symbol whose attachment has changed, which requires clearing
; of the corresponding memo table.

  (let* ((ext-anc-attachments
          (access memoize-info-ht-entry entry :ext-anc-attachments))
         (valid-p
          (if (eq fns :clear)
              :clear
            (or (null ext-anc-attachments)
                (ext-anc-attachments-valid-p fns ext-anc-attachments wrld t)))))
    (cond ((eq valid-p t) (mv nil entry))
          (t
           (mv (if (eq valid-p nil) t valid-p)
               (change memoize-info-ht-entry entry
                       :ext-anc-attachments
                       (extended-ancestors (access memoize-info-ht-entry entry
                                                   :fn)
                                           wrld)))))))

(defun update-memo-entries-for-attachments (fns wrld state)
  (let ((ctx 'top-level)
        (fns (if (eq fns :clear)
                 fns
               (strict-merge-sort-symbol-<
                (loop for fn in fns
                      collect (canonical-sibling fn wrld))))))
    (when (eq fns :clear)
      (observation ctx
                   "Memoization tables for functions memoized with :AOKP T ~
                    are being cleared."))
    (when fns ; optimization
      (maphash (lambda (k entry)
                 (when (symbolp k)
                   (mv-let (changedp new-entry)
                           (update-memo-entry-for-attachments fns entry wrld)
                           (when changedp
                             (when (not (or (eq changedp t)
                                            (eq fns :clear)))
                               (observation ctx
                                            "Memoization table for function ~x0 ~
                                           is being cleared because ~
                                           attachment to function ~x1 has ~
                                           changed."
                                            k changedp)
                               (clear-one-memo-and-pons-hash entry))
                             (setf (gethash k *memoize-info-ht*)
                                   new-entry)))))
               *memoize-info-ht*))))