(in-package :cmp)

;; A function of two arguments, an LLVM Value and a variable.
;; The "variable" is just whatever is provided to this code
;; (so that it can work with either b or c clasp).
;; The function should put the Value into the variable, possibly generating code to do so.
;; In order to work with cclasp's SSA stuff, it must be called exactly once for each variable.
(defvar *argument-out*)

(defun compile-wrong-number-arguments-block (closure nargs min max)
  ;; make a new irbuilder, so as to not disturb anything
  (with-irbuilder ()
    (let ((errorb (irc-basic-block-create "wrong-num-args")))
      (irc-begin-block errorb)
      (irc-intrinsic "cc_wrong_number_of_arguments"
                     ;; We use low max to indicate no upper limit.
                     closure nargs min (or max (irc-size_t 0)))
      (irc-unreachable)
      errorb)))

;; Generate code to signal an error iff there weren't enough arguments provided.
(defun compile-error-if-not-enough-arguments (error-block cmin nargs)
  (let* ((cont-block (irc-basic-block-create "enough-arguments"))
         (cmp (irc-icmp-ult nargs cmin)))
    (irc-cond-br cmp error-block cont-block)
    (irc-begin-block cont-block)))

;; Ditto but with too many.
(defun compile-error-if-too-many-arguments (error-block cmax nargs)
  (let* ((cont-block (irc-basic-block-create "enough-arguments"))
         (cmp (irc-icmp-ugt nargs cmax)))
    (irc-cond-br cmp error-block cont-block)
    (irc-begin-block cont-block)))

;; Generate code to bind the required arguments.
(defun compile-required-arguments (reqargs cc)
  ;; reqargs is as returned from process-lambda-list- (# ...) where # is the count.
  ;; cc is the calling-convention object.
  (dolist (req (cdr reqargs))
    (let ((arg (calling-convention-vaslist.va-arg cc)))
      (funcall *argument-out* arg req))))

;;; Unlike the other compile-*-arguments, this one returns a value-
;;; an LLVM Value for the number of arguments remaining.
(defun compile-optional-arguments (optargs nreq calling-conv false true)
  ;; optargs is (# var suppliedp default ...)
  ;; We basically generate a switch, but also return the number of arguments remaining
  ;; (or zero if that's negative).
  ;; For (&optional a b) for example,
  #|
size_t nargs_remaining;
switch (nargs) {
  case 0: nargs_remaining = 0; a = [nil]; a_p = [nil]; b = [nil]; b_p = [nil]; break;
  case 1: nargs_remaining = 0; a = va_arg(); a_p = [t]; b = [nil]; b_p = [nil]; break;
  default: nargs_remaining = nargs - 2; a = va_arg(); a_p = [t]; b = va_arg(); b_p = [t]; break;
}
  |#
  ;; All these assignments are done with phi so it's a bit more confusing to follow, unfortunately.
  (let* ((nargs (calling-convention-nargs calling-conv))
         (nopt (first optargs))
         (nfixed (+ nopt nreq))
         (opts (rest optargs))
         (enough (irc-basic-block-create "enough-for-optional"))
         (undef (irc-undef-value-get %t*%))
         (sw (irc-switch nargs enough nopt))
         (assn (irc-basic-block-create "optional-assignments"))
         (final (irc-basic-block-create "done-parsing-optionals"))
         (zero (irc-size_t 0)))
    ;; We generate the assignments first, although they occur last.
    ;; It's just a bit more convenient to do that way.
    (irc-begin-block assn)
    (let* ((npreds (1+ nopt))
           (nremaining (irc-phi %size_t% npreds "nargs-remaining"))
           (var-phis nil) (suppliedp-phis nil))
      ;; We have to do this in two loops to ensure the PHIs come before any code
      ;; generated by *argument-out*.
      (dotimes (i nopt)
        (push (irc-phi %t*% npreds) suppliedp-phis)
        (push (irc-phi %t*% npreds) var-phis))
      ;; OK _now_ argument-out
      (do* ((cur-opt opts (cdddr cur-opt))
            (var (car cur-opt) (car cur-opt))
            (suppliedp (cadr cur-opt) (cadr cur-opt))
            (var-phis var-phis (cdr var-phis))
            (var-phi (car var-phis) (car var-phis))
            (suppliedp-phis suppliedp-phis (cdr suppliedp-phis))
            (suppliedp-phi (car suppliedp-phis) (car suppliedp-phis)))
           ((endp cur-opt))
        (funcall *argument-out* suppliedp-phi suppliedp)
        (funcall *argument-out* var-phi var))
      (irc-br final)
      ;; Generate a block for each case.
      (do ((i nreq (1+ i)))
          ((= i nfixed))
        (let ((new (irc-basic-block-create (core:fmt nil "supplied-{}-arguments" i))))
          (llvm-sys:add-case sw (irc-size_t i) new)
          (irc-phi-add-incoming nremaining zero new)
          (irc-begin-block new)
          ;; Assign each optional parameter accordingly.
          (do* ((var-phis var-phis (cdr var-phis))
                (var-phi (car var-phis) (car var-phis))
                (suppliedp-phis suppliedp-phis (cdr suppliedp-phis))
                (suppliedp-phi (car suppliedp-phis) (car suppliedp-phis))
                (j nreq (1+ j))
                (enough (< j i) (< j i)))
               ((endp var-phis))
            (irc-phi-add-incoming suppliedp-phi (if enough true false) new)
            (irc-phi-add-incoming var-phi (if enough (calling-convention-vaslist.va-arg calling-conv) undef) new))
          (irc-br assn)))
      ;; Default case: everything gets a value and a suppliedp=T.
      (irc-begin-block enough)
      (irc-phi-add-incoming nremaining (irc-sub nargs (irc-size_t nfixed)) enough)
      (dolist (suppliedp-phi suppliedp-phis)
        (irc-phi-add-incoming suppliedp-phi true enough))
      (dolist (var-phi var-phis)
        (irc-phi-add-incoming var-phi (calling-convention-vaslist.va-arg calling-conv) enough))
      (irc-br assn)
      ;; ready to generate more code
      (irc-begin-block final)
      nremaining)))

(defun compile-rest-argument (rest-var varest-p nremaining calling-conv)
  (cmp:irc-branch-to-and-begin-block (cmp:irc-basic-block-create "process-rest-argument"))
  (when rest-var
    (let* ((rest-alloc (calling-convention-rest-alloc calling-conv))
	   (rest (cond
                   ((eq rest-alloc 'ignore)
                    ;; &rest variable is ignored- allocate nothing
                    (irc-undef-value-get %t*%))
                   ((eq rest-alloc 'dynamic-extent)
                    ;; Do the dynamic extent thing- alloca, then an intrinsic to initialize it.
                    (let ((rrest (alloca-dx-list :length nremaining :label "rrest")))
                      (irc-intrinsic "cc_gatherDynamicExtentRestArguments"
                                     (cmp:calling-convention-vaslist* calling-conv)
                                     nremaining
                                     (irc-bit-cast rrest %t**%))))
                   (varest-p
                    #+(or)
                    (irc-tag-vaslist (cmp:calling-convention-vaslist* calling-conv)
                                     "rest")
                    ;;#+(or)
                    (let ((temp-vaslist (alloca-vaslist :label "rest")))
                      (irc-intrinsic "cc_gatherVaRestArguments" 
                                     (cmp:calling-convention-vaslist* calling-conv)
                                     nremaining
                                     temp-vaslist)))
                   (t
                    ;; general case- heap allocation
                    (irc-intrinsic "cc_gatherRestArguments" 
                                   (cmp:calling-convention-vaslist* calling-conv)
                                   nremaining)))))
      (funcall *argument-out* rest rest-var))))

;;; Keyword processing is the most complicated part, unsurprisingly.
#|
Here is pseudo-C for the parser for (&key a). [foo] indicates an inserted constant.
Having to write with phi nodes unfortunately makes things rather more confusing.

if ((remaining_nargs % 2) == 1)
  cc_oddKeywordException([*current-function-description*]);
tstar bad_keyword = undef;
bool seen_bad_keyword = false;
t_star a_temp = undef, a_p_temp = [nil], allow_other_keys_temp = [nil], allow_other_keys_p_temp = [nil];
for (; remaining_nargs != 0; remaining_nargs -= 2) {
  tstar key = va_arg(vaslist), value = va_arg(vaslist);
  if (key == [:a]) {
    if (a_p_temp == [nil]) {
      a_p_temp = [t]; a_temp = value; continue;
    } else continue;
  }
  if (key == [:allow-other-keys]) {
    if (allow_other_keys_p_temp == [nil]) {
      allow_other_keys_p_temp = [t]; allow_other_keys_temp = value; continue;
    } else continue;
  }
  seen_bad_keyword = true; bad_keyword = key;
}
if (seen_bad_keyword)
  cc_ifBadKeywordArgumentException(allow_other_keys_temp, bad_keyword, [*current-function-description*]);
a_p = a_p_temp; a = a_temp;
|#

(defun compile-one-key-test (keyword key-arg suppliedp-phi cont-block false)
  (let* ((keystring (string keyword))
         ;; NOTE: We might save a bit of time by moving this out of the loop.
         ;; Or maybe LLVM can handle it. I don't know.
         (key-const (clasp-cleavir::literal keyword))
         (match (irc-basic-block-create (core:fmt nil "matched-{}" keystring)))
         (mismatch (irc-basic-block-create (core:fmt nil "not-{}" keystring))))
    (let ((test (irc-icmp-eq key-arg key-const)))
      (irc-cond-br test match mismatch))
    (irc-begin-block match)
    (let* ((new (irc-basic-block-create (core:fmt nil "new-{}" keystring)))
           (old (irc-basic-block-create (core:fmt nil "old-{}" keystring))))
      (let ((test (irc-icmp-eq suppliedp-phi false)))
        (irc-cond-br test new old))
      (irc-begin-block new) (irc-br cont-block)
      (irc-begin-block old) (irc-br cont-block)
      (irc-begin-block mismatch)
      (values new old))))
  
(defun compile-key-arguments (keyargs lambda-list-aokp nremaining calling-conv false true)
  (macrolet ((do-keys ((keyword) &body body)
               `(do* ((cur-key (cdr keyargs) (cddddr cur-key))
                      (,keyword (car cur-key) (car cur-key)))
                     ((endp cur-key))
                  ,@body)))
    (let ((aok-parameter-p nil)
          allow-other-keys
          (nkeys (car keyargs))
          (undef (irc-undef-value-get %t*%))
          (start (irc-basic-block-create "parse-key-arguments"))
          (matching (irc-basic-block-create "match-keywords"))
          (after (irc-basic-block-create "after-kw-loop"))
          (unknown-kw (irc-basic-block-create "unknown-kw"))
          (kw-loop (irc-basic-block-create "kw-loop"))
          (kw-loop-continue (irc-basic-block-create "kw-loop-continue")))
      ;; Prepare for :allow-other-keys.
      (unless lambda-list-aokp
        ;; Is there an allow-other-keys argument?
        (do-keys (key)
          (when (eq key :allow-other-keys) (setf aok-parameter-p t) (return)))
        ;; If there's no allow-other-keys argument, add one.
        (unless aok-parameter-p
          (setf keyargs (list* (1+ (car keyargs))
                               ;; default, var, and suppliedp are of course dummies.
                               ;; At the end we can check aok-parameter-p to avoid
                               ;; actually assigning to them.
                               :allow-other-keys nil nil nil
                               (cdr keyargs)))))
      (irc-branch-to-and-begin-block start)
      ;; If the number of arguments remaining is odd, the call is invalid- error.
      (let* ((odd-kw (irc-basic-block-create "odd-kw"))
             (rem (irc-srem nremaining (irc-size_t 2))) ; parity
             (evenp (irc-icmp-eq rem (irc-size_t 0)))) ; is parity zero (is SUB even)?
        (irc-cond-br evenp kw-loop odd-kw)
        ;; There have been an odd number of arguments, so signal an error.
        (irc-begin-block odd-kw)
        (unless (calling-convention-closure calling-conv)
          (error "The calling-conv ~s does not have a closure" calling-conv))
        (irc-intrinsic "cc_oddKeywordException"
                       (calling-convention-closure calling-conv))
        (irc-unreachable))
      ;; Loop starts; welcome hell
      (irc-begin-block kw-loop)
      (let ((top-param-phis nil) (top-suppliedp-phis nil)
            (new-blocks nil) (old-blocks nil)
            (nargs-remaining (irc-phi %size_t% 2 "nargs-remaining"))
            (sbkw (irc-phi %i1% 2 "seen-bad-keyword"))
            (bad-keyword (irc-phi %t*% 2 "bad-keyword")))
        (irc-phi-add-incoming nargs-remaining nremaining start)
        (irc-phi-add-incoming sbkw (jit-constant-false) start)
        (irc-phi-add-incoming bad-keyword undef start)
        (do-keys (key)
          (let ((var-phi (irc-phi %t*% 2 (core:fmt nil "{}-top" (string key)))))
            (push var-phi top-param-phis)
            ;; If we're paying attention to :allow-other-keys, track it specially
            ;; and initialize it to NIL.
            (cond ((and (not lambda-list-aokp) (eq key :allow-other-keys))
                   (irc-phi-add-incoming var-phi false start)
                   (setf allow-other-keys var-phi))
                  (t (irc-phi-add-incoming var-phi undef start))))
          (let ((suppliedp-phi (irc-phi %t*% 2 (core:fmt nil "{}-suppliedp-top" (string key)))))
            (push suppliedp-phi top-suppliedp-phis)
            (irc-phi-add-incoming suppliedp-phi false start)))
        (setf top-param-phis (nreverse top-param-phis)
              top-suppliedp-phis (nreverse top-suppliedp-phis))
        ;; Are we done?
        (let ((zerop (irc-icmp-eq nargs-remaining (irc-size_t 0))))
          (irc-cond-br zerop after matching))
        (irc-begin-block matching)
        ;; Start matching keywords
        (let ((key-arg (calling-convention-vaslist.va-arg calling-conv))
              (value-arg (calling-convention-vaslist.va-arg calling-conv)))
          (do* ((cur-key (cdr keyargs) (cddddr cur-key))
                (key (car cur-key) (car cur-key))
                (suppliedp-phis top-suppliedp-phis (cdr suppliedp-phis))
                (suppliedp-phi (car suppliedp-phis) (car suppliedp-phis)))
               ((endp cur-key))
            (multiple-value-bind (new-block old-block)
                (compile-one-key-test key key-arg suppliedp-phi kw-loop-continue false)
              (push new-block new-blocks) (push old-block old-blocks)))
          (setf new-blocks (nreverse new-blocks) old-blocks (nreverse old-blocks))
          ;; match failure - as usual, works through phi
          (irc-branch-to-and-begin-block unknown-kw)
          (irc-br kw-loop-continue)
          ;; Go around again. And do most of the actual work in phis.
          (irc-begin-block kw-loop-continue)
          (let ((npreds (1+ (* 2 nkeys)))) ; two for each key, plus one for unknown-kw.
            (let ((bot-sbkw (irc-phi %i1% npreds "seen-bad-keyword-bottom"))
                  (bot-bad-keyword (irc-phi %t*% npreds "bad-keyword-bottom")))
              ;; Set up the top to use these.
              (irc-phi-add-incoming sbkw bot-sbkw kw-loop-continue)
              (irc-phi-add-incoming bad-keyword bot-bad-keyword kw-loop-continue)
              ;; If we're coming from unknown-kw, store that.
              (irc-phi-add-incoming bot-sbkw (jit-constant-true) unknown-kw)
              (irc-phi-add-incoming bot-bad-keyword key-arg unknown-kw)
              ;; If we're coming from a match block, don't change anything.
              (dolist (new-block new-blocks)
                (irc-phi-add-incoming bot-sbkw sbkw new-block)
                (irc-phi-add-incoming bot-bad-keyword bad-keyword new-block))
              (dolist (old-block old-blocks)
                (irc-phi-add-incoming bot-sbkw sbkw old-block)
                (irc-phi-add-incoming bot-bad-keyword bad-keyword old-block)))
            ;; OK now the actual keyword values.
            (do* ((var-new-blocks new-blocks (cdr var-new-blocks))
                  (var-new-block (car var-new-blocks) (car var-new-blocks))
                  (top-param-phis top-param-phis (cdr top-param-phis))
                  (top-param-phi (car top-param-phis) (car top-param-phis))
                  (top-suppliedp-phis top-suppliedp-phis (cdr top-suppliedp-phis))
                  (top-suppliedp-phi (car top-suppliedp-phis) (car top-suppliedp-phis)))
                 ((endp var-new-blocks))
              (let ((var-phi (irc-phi %t*% npreds))
                    (suppliedp-phi (irc-phi %t*% npreds)))
                ;; fix up the top part to take values from here
                (irc-phi-add-incoming top-param-phi var-phi kw-loop-continue)
                (irc-phi-add-incoming top-suppliedp-phi suppliedp-phi kw-loop-continue)
                ;; If coming from unknown-kw we keep our values the same.
                (irc-phi-add-incoming var-phi top-param-phi unknown-kw)
                (irc-phi-add-incoming suppliedp-phi top-suppliedp-phi unknown-kw)
                ;; All new-blocks other than this key's stick with what they have.
                (dolist (new-block new-blocks)
                  (cond ((eq var-new-block new-block)
                         ;; Here, however, we get the new values
                         (irc-phi-add-incoming var-phi value-arg new-block)
                         (irc-phi-add-incoming suppliedp-phi true new-block))
                        (t
                         (irc-phi-add-incoming var-phi top-param-phi new-block)
                         (irc-phi-add-incoming suppliedp-phi top-suppliedp-phi new-block))))
                ;; All old-blocks stick with what they have.
                (dolist (old-block old-blocks)
                  (irc-phi-add-incoming var-phi top-param-phi old-block)
                  (irc-phi-add-incoming suppliedp-phi top-suppliedp-phi old-block))))))
        (let ((dec (irc-sub nargs-remaining (irc-size_t 2))))
          (irc-phi-add-incoming nargs-remaining dec kw-loop-continue))
        (irc-br kw-loop)
        ;; Loop over.
        (irc-begin-block after)
        ;; If we hit a bad keyword, and care, signal an error.
        (unless lambda-list-aokp
          (let ((aok-check (irc-basic-block-create "aok-check"))
                (kw-assigns (irc-basic-block-create "kw-assigns")))
            (irc-cond-br sbkw aok-check kw-assigns)
            (irc-begin-block aok-check)
            (irc-intrinsic
             "cc_ifBadKeywordArgumentException"
             ;; aok was initialized to NIL, regardless of the suppliedp, so this is ok.
             allow-other-keys bad-keyword (calling-convention-closure calling-conv))
            (irc-br kw-assigns)
            (irc-begin-block kw-assigns)))
        (do* ((top-param-phis top-param-phis (cdr top-param-phis))
              (top-param-phi (car top-param-phis) (car top-param-phis))
              (top-suppliedp-phis top-suppliedp-phis (cdr top-suppliedp-phis))
              (top-suppliedp-phi (car top-suppliedp-phis) (car top-suppliedp-phis))
              (cur-key (cdr keyargs) (cddddr cur-key))
              (key (car cur-key) (car cur-key))
              (var (caddr cur-key) (caddr cur-key))
              (suppliedp (cadddr cur-key) (cadddr cur-key)))
             ((endp cur-key))
          (when (or (not (eq key :allow-other-keys)) lambda-list-aokp aok-parameter-p)
            (funcall *argument-out* top-param-phi var)
            (funcall *argument-out* top-suppliedp-phi suppliedp)))))))

(defun compile-general-lambda-list-code (reqargs 
					 optargs 
					 rest-var
                                         varest-p
					 key-flag 
					 keyargs 
					 allow-other-keys
					 calling-conv
                                         &key argument-out (safep t))
  (let* ((*argument-out* argument-out)
         (nargs (calling-convention-nargs calling-conv))
         (nreq (car reqargs))
         (nopt (car optargs))
         (nfixed (+ nreq nopt))
         (creq (irc-size_t nreq))
         (cmax (if (or rest-var key-flag)
                   nil
                   (irc-size_t nfixed)))
         (wrong-nargs-block
           (when safep
             (compile-wrong-number-arguments-block
              (calling-convention-closure calling-conv)
              nargs creq cmax))))
    (unless (zerop nreq)
      (when safep
        (compile-error-if-not-enough-arguments wrong-nargs-block creq nargs))
      (compile-required-arguments reqargs calling-conv))
    (let (;; NOTE: Sometimes we don't actually need these.
          ;; We could save miniscule time by not generating.
          (iNIL (clasp-cleavir::%nil)) (iT (clasp-cleavir::%t)))
      (if (or rest-var key-flag)
          ;; We have &key and/or &rest, so parse with that expectation.
          ;; Specifically, we have to get a variable for how many arguments are left after &optional.
          (let ((nremaining
                  (if (zerop nopt)
                      ;; With no optional arguments it's trivial.
                      (irc-sub nargs creq "nremaining")
                      ;; Otherwise
                      (compile-optional-arguments optargs nreq calling-conv iNIL iT))))
            ;; Note that we don't need to check for too many arguments here.
            (when rest-var
              (compile-rest-argument rest-var varest-p nremaining calling-conv))
            (when key-flag
              (compile-key-arguments keyargs (or allow-other-keys (not safep))
                                     nremaining calling-conv iNIL iT)))
          ;; We don't have &key or &rest, but we might still have &optional.
          (progn
            (unless (zerop nopt)
              ;; Return value of compile-optional-arguments is unneeded-
              ;; we could use it in the error check to save a subtraction, though.
              (compile-optional-arguments optargs nreq calling-conv iNIL iT))
            (when safep
              (compile-error-if-too-many-arguments wrong-nargs-block cmax nargs)))))))


        
  
(defun compile-only-req-and-opt-arguments (arity cleavir-lambda-list-analysis calling-conv &key argument-out (safep t))
  (multiple-value-bind (reqargs optargs)
      (process-cleavir-lambda-list-analysis cleavir-lambda-list-analysis)
    (let* ((register-args (calling-convention-register-args calling-conv))
           (nargs (calling-convention-nargs calling-conv))
           (nreq (car (cleavir-lambda-list-analysis-required cleavir-lambda-list-analysis)))
           (creq (irc-size_t nreq))
           (nopt (car (cleavir-lambda-list-analysis-optional cleavir-lambda-list-analysis)))
           (cmax (irc-size_t (+ nreq nopt)))
           (error-block
             ;; see kludge above
             (when safep
               (compile-wrong-number-arguments-block
                (calling-convention-closure calling-conv)
                nargs creq cmax))))
      ;; fixme: it would probably be nicer to generate one switch such that not-enough-arguments
      ;; goes to an error block and too-many goes to another. then we'll only have one test on
      ;; the argument count. llvm might reduce it to that anyway, though.
      (flet ((ensure-register (registers undef &optional name)
               (declare (ignore name))
               (let ((register (car registers)))
                 (if register
                     register
                     undef))))
        (unless (cmp:generate-function-for-arity-p arity cleavir-lambda-list-analysis)
          (let ((error-block (compile-wrong-number-arguments-block (calling-convention-closure calling-conv)
                                                                   (jit-constant-i64 (length register-args))
                                                                   (jit-constant-i64 nreq)
                                                                   (jit-constant-i64 (+ nreq nopt)))))
            (irc-br error-block)
            (return-from compile-only-req-and-opt-arguments nil)))
        ;; required arguments
        (when (> nreq 0)
          (when safep
            (compile-error-if-not-enough-arguments error-block creq nargs))
          (dolist (req (cdr reqargs))
            ;; we pop the register-args so that the optionals below won't use em.
            (funcall argument-out (pop register-args) req)))
        ;; optional arguments. code is mostly the same as compile-optional-arguments (fixme).
        (if (> nopt 0)
            (let* ((npreds (1+ nopt))
                   (undef (irc-undef-value-get %t*%))
                   (true (clasp-cleavir::%t))
                   (false (clasp-cleavir::%nil))
                   (default (irc-basic-block-create "enough-for-optional"))
                   (assn (irc-basic-block-create "optional-assignments"))
                   (after (irc-basic-block-create "argument-parsing-done"))
                   (sw (irc-switch nargs default nopt))
                   (var-phis nil) (suppliedp-phis nil))
              (irc-begin-block assn)
              (dotimes (i nopt)
                (push (irc-phi %t*% npreds) var-phis)
                (push (irc-phi %t*% npreds) suppliedp-phis))
              (do ((cur-opt (cdr optargs) (cdddr cur-opt))
                   (var-phis var-phis (cdr var-phis))
                   (suppliedp-phis suppliedp-phis (cdr suppliedp-phis)))
                  ((endp cur-opt))
                (funcall argument-out (car suppliedp-phis) (second cur-opt))
                (funcall argument-out (car var-phis) (first cur-opt)))
              (irc-br after)
              ;; each case
              (dotimes (i nopt)
                (let* ((opti (+ i nreq))
                       (blck (irc-basic-block-create (core:fmt nil "supplied-{}-arguments" opti))))
                  (llvm-sys:add-case sw (irc-size_t opti) blck)
                  (do ((var-phis var-phis (cdr var-phis))
                       (suppliedp-phis suppliedp-phis (cdr suppliedp-phis))
                       (registers register-args (cdr registers))
                       (optj nreq (1+ optj)))
                      ((endp var-phis))
                    (cond ((< optj opti) ; enough arguments
                           (irc-phi-add-incoming (car suppliedp-phis) true blck)
                           (irc-phi-add-incoming (car var-phis) (ensure-register registers undef :nopt) blck))
                          (t            ; nope
                           (irc-phi-add-incoming (car suppliedp-phis) false blck)
                           (irc-phi-add-incoming (car var-phis) undef blck))))
                  (irc-begin-block blck) (irc-br assn)))
              ;; default
              ;; just use a register for each argument
              ;; we have to use another block because compile-error-etc does an invoke
              ;; and generates more blocks.
              (let ((default-cont (irc-basic-block-create "enough-for-optional-continued")))
                (do ((var-phis var-phis (cdr var-phis))
                     (suppliedp-phis suppliedp-phis (cdr suppliedp-phis))
                     (registers register-args (cdr registers)))
                    ((endp var-phis))
                  (irc-phi-add-incoming (car suppliedp-phis) true default-cont)
                  (irc-phi-add-incoming (car var-phis) (ensure-register registers undef :var-phis) default-cont))
                (irc-begin-block default)
                ;; test for too many arguments
                (when safep
                  (compile-error-if-too-many-arguments error-block cmax nargs))
                (irc-branch-to-and-begin-block default-cont)
                (irc-br assn)
                ;; and, done.
                (irc-begin-block after)))
            ;; no optional arguments, so not much to do
            (when safep
              (compile-error-if-too-many-arguments error-block cmax nargs))))
      t)))

(defun req-opt-only-p (cleavir-lambda-list)
  (let ((nreq 0) (nopt 0) (req-opt-only t)
        (state nil))
    (dolist (item cleavir-lambda-list)
      (cond ((eq item '&optional)
             (if (eq state '&optional)
                 (progn (setf req-opt-only nil) ; dupe &optional; just mark as general
                        (return))
                 (setf state '&optional)))
            ((member item lambda-list-keywords)
             (setf req-opt-only nil)
             (return))
            (t (if (eq state '&optional)
                   (incf nopt)
                   (incf nreq)))))
    (values req-opt-only nreq nopt)))

(defun lambda-list-arguments (lambda-list)
  (multiple-value-bind (reqargs optargs rest-var key-flag keyargs allow-other-keys auxargs varest-p)
      (core:process-lambda-list lambda-list 'function)
    (declare (ignore auxargs allow-other-keys varest-p key-flag))
    (let ((args '()))
      (dolist (req (rest reqargs))
        (push req args))
      (do ((cur (rest optargs) (cdddr cur)))
          ((null cur) nil)
        (let ((opt-name (car cur))
              (opt-flag (cadr cur)))
          (push opt-name args)
          (when opt-flag (push opt-flag args))))
      (when rest-var (push rest-var args))
      (do ((cur (rest keyargs) (cddddr cur)))
          ((null cur) nil)
        (let ((key-name (caddr cur))
              (key-flag (cadddr cur)))
          (push key-name args)
          (when key-flag (push key-flag args))))
      (nreverse args))))

(defun calculate-cleavir-lambda-list-analysis (lambda-list)
  ;; we assume that the lambda list is in its correct format:
  ;; 1) required arguments are lexical locations.
  ;; 2) optional arguments are (<lexical location> <lexical location>)
  ;; 3) keyword arguments are (<symbol> <lexical location> <lexical location>)
  ;; this lets us cheap out on parsing, except &rest and &allow-other-keys.
  (let (required optional rest-type rest key aok-p key-flag
                 (required-count 0) (optional-count 0) (key-count 0))
    (dolist (item lambda-list)
      (case item
        ((&optional) #|ignore|#)
        ((&key) (setf key-flag t))
        ((&rest core:&va-rest) (setf rest-type item))
        ((&allow-other-keys) (setf aok-p t))
        (t (if (listp item)
               (cond ((= (length item) 2)
                      ;; optional
                      (incf optional-count)
                      ;; above, we expect (location -p whatever)
                      ;; though it's specified as (var init -p)
                      ;; fix me
                      (push (first item) optional)
                      (push (second item) optional)
                      (push nil optional))
                     (t ;; key, assumedly
                      (incf key-count)
                      (push (first item) key)
                      (push (first item) key)
                      ;; above, we treat this as being the location,
                      ;; even though from process-lambda-list it's
                      ;; the initform.
                      ;; this file needs work fixme.
                      (push (second item) key)
                      (push (third item) key)))
               ;; nonlist; we picked off lambda list keywords, so it's an argument.
               (cond (rest-type
                      ;; we've seen a &rest lambda list keyword, so this must be that
                      (setf rest item))
                     ;; haven't seen anything, it's required
                     (t (incf required-count)
                        (push item required)))))))
    (let* ((cleavir-lambda-list (ensure-cleavir-lambda-list lambda-list))
           (arguments (lambda-list-arguments cleavir-lambda-list)))
      (make-cleavir-lambda-list-analysis
       :cleavir-lambda-list (ensure-cleavir-lambda-list lambda-list) ; Is this correct?
       :req-opt-only-p (req-opt-only-p (ensure-cleavir-lambda-list lambda-list))
       :lambda-list-arguments arguments
       :required (cons required-count (nreverse required))
       :optional (cons optional-count (nreverse optional))
       :rest rest
       :key-flag key-flag
       :key-count (cons key-count (nreverse key))
       :aok-p aok-p
       :aux-p nil                       ; aux-p; unused here
       :va-rest-p (if (eq rest-type 'core:&va-rest) t nil)))))



(defun may-use-only-registers (cleavir-lambda-list-analysis)
  (multiple-value-bind (req-opt-only nreq nopt)
      (req-opt-only-p (cleavir-lambda-list-analysis-cleavir-lambda-list cleavir-lambda-list-analysis))
    (and req-opt-only
         (and (<= +entry-point-arity-begin+ (+ nreq nopt))
              (< (+ nreq nopt) +entry-point-arity-end+)))))

;;; compile-lambda-list-code
;;; you must provide the following lambdas
;;;   alloca-size_t (label) that allocas a size_t slot in the current function
;;;   alloca-vaslist (label) that allocas a vaslist slot in the current function
;;;   translate-datum (datum) that translates a datum into an alloca in the current function
;;;
(defun compile-lambda-list-code (cleavir-lambda-list-analysis calling-conv arity
                                 &key argument-out (safep t))
  "Return T if arguments were processed and NIL if they were not"
  (multiple-value-bind (reqargs optargs rest-var key-flag keyargs allow-other-keys unused-auxs varest-p)
      (process-cleavir-lambda-list-analysis cleavir-lambda-list-analysis)
    (declare (ignore unused-auxs))
    (cond
      ((eq arity :general-entry)
       (compile-general-lambda-list-code reqargs 
                                         optargs 
                                         rest-var
                                         varest-p
                                         key-flag 
                                         keyargs 
                                         allow-other-keys
                                         calling-conv
                                         :argument-out argument-out
                                         :safep safep)
       t ;; always successful for general lambda-list processing
       )
      ((and (fixnump arity)
            (may-use-only-registers cleavir-lambda-list-analysis))
       (let ((result (compile-only-req-and-opt-arguments arity cleavir-lambda-list-analysis #|reqargs optargs|#
                                                         calling-conv
                                                         :argument-out argument-out
                                                         :safep safep)))
         result                         ; may be nil or t
         ))
      (t (let* ((register-args (calling-convention-register-args calling-conv))
                (nargs (length register-args))
                (arg-buffer (if (= nargs 0)
                                nil
                                (alloca-arguments nargs "ll-args")))
                (vaslist* (alloca-vaslist))
                (idx 0))
           (dolist (arg register-args)
             (let ((arg-gep (irc-typed-gep (llvm-sys:array-type-get %t*% nargs) arg-buffer (list 0 idx))))
               (incf idx)
               (irc-store arg arg-gep)))
           (if (= nargs 0)
               (vaslist-start vaslist* (jit-constant-i64 nargs))
               (vaslist-start vaslist* (jit-constant-i64 nargs)
                              (irc-bit-cast arg-buffer %i8**%)))
           (setf (calling-convention-vaslist* calling-conv) vaslist*)
           (compile-general-lambda-list-code reqargs 
                                             optargs 
                                             rest-var
                                             varest-p
                                             key-flag 
                                             keyargs 
                                             allow-other-keys
                                             calling-conv
                                             :argument-out argument-out
                                             :safep safep)
           )
         t ;; always successful when using general lambda-list processing
         ))))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; Setup the calling convention
;;
(defun setup-calling-convention (llvm-function arity
                                 &key debug-on rest-alloc cleavir-lambda-list-analysis)
    (initialize-calling-convention llvm-function
                                   arity
                                   :debug-on debug-on
                                   :rest-alloc rest-alloc
                                   :cleavir-lambda-list-analysis cleavir-lambda-list-analysis))
