X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Flocall.lisp;h=ed6f948b38e49cb73542cb76c51ed1798e0d5663;hb=993d5b779638756473181dda8d928d33038d4cc3;hp=eb93a019b782346fd3743d7265f90c8683951bce;hpb=a530bbe337109d898d5b4a001fc8f1afa3b5dc39;p=sbcl.git diff --git a/src/compiler/locall.lisp b/src/compiler/locall.lisp index eb93a01..ed6f948 100644 --- a/src/compiler/locall.lisp +++ b/src/compiler/locall.lisp @@ -21,9 +21,6 @@ (in-package "SB!C") -(file-comment - "$Header$") - ;;; This function propagates information from the variables in the function ;;; Fun to the actual arguments in Call. This is also called by the VALUES IR1 ;;; optimizer when it sleazily converts MV-BINDs to LETs. @@ -98,65 +95,61 @@ ;;;; external entry point creation -;;; Return a Lambda form that can be used as the definition of the XEP for Fun. +;;; Return a Lambda form that can be used as the definition of the XEP +;;; for FUN. ;;; -;;; If Fun is a lambda, then we check the number of arguments (conditional -;;; on policy) and call Fun with all the arguments. +;;; If FUN is a lambda, then we check the number of arguments +;;; (conditional on policy) and call FUN with all the arguments. ;;; -;;; If Fun is an Optional-Dispatch, then we dispatch off of the number of -;;; supplied arguments by doing do an = test for each entry-point, calling the -;;; entry with the appropriate prefix of the passed arguments. +;;; If FUN is an OPTIONAL-DISPATCH, then we dispatch off of the number +;;; of supplied arguments by doing do an = test for each entry-point, +;;; calling the entry with the appropriate prefix of the passed +;;; arguments. ;;; -;;; If there is a more arg, then there are a couple of optimizations that we -;;; make (more for space than anything else): -;;; -- If Min-Args is 0, then we make the more entry a T clause, since no -;;; argument count error is possible. -;;; -- We can omit the = clause for the last entry-point, allowing the case of -;;; 0 more args to fall through to the more entry. +;;; If there is a more arg, then there are a couple of optimizations +;;; that we make (more for space than anything else): +;;; -- If MIN-ARGS is 0, then we make the more entry a T clause, since +;;; no argument count error is possible. +;;; -- We can omit the = clause for the last entry-point, allowing the +;;; case of 0 more args to fall through to the more entry. ;;; -;;; We don't bother to policy conditionalize wrong arg errors in optional -;;; dispatches, since the additional overhead is negligible compared to the -;;; other hair going down. +;;; We don't bother to policy conditionalize wrong arg errors in +;;; optional dispatches, since the additional overhead is negligible +;;; compared to the cost of everything else going on. ;;; -;;; Note that if policy indicates it, argument type declarations in Fun will -;;; be verified. Since nothing is known about the type of the XEP arg vars, -;;; type checks will be emitted when the XEP's arg vars are passed to the -;;; actual function. +;;; Note that if policy indicates it, argument type declarations in +;;; Fun will be verified. Since nothing is known about the type of the +;;; XEP arg vars, type checks will be emitted when the XEP's arg vars +;;; are passed to the actual function. (defun make-xep-lambda (fun) (declare (type functional fun)) (etypecase fun (clambda (let ((nargs (length (lambda-vars fun))) - (n-supplied (gensym))) - (collect ((temps)) - (dotimes (i nargs) - (temps (gensym))) - `(lambda (,n-supplied ,@(temps)) - (declare (type index ,n-supplied)) - ,(if (policy nil (zerop safety)) - `(declare (ignore ,n-supplied)) - `(%verify-argument-count ,n-supplied ,nargs)) - (%funcall ,fun ,@(temps)))))) + (n-supplied (gensym)) + (temps (make-gensym-list (length (lambda-vars fun))))) + `(lambda (,n-supplied ,@temps) + (declare (type index ,n-supplied)) + ,(if (policy nil (zerop safety)) + `(declare (ignore ,n-supplied)) + `(%verify-argument-count ,n-supplied ,nargs)) + (%funcall ,fun ,@temps)))) (optional-dispatch (let* ((min (optional-dispatch-min-args fun)) (max (optional-dispatch-max-args fun)) (more (optional-dispatch-more-entry fun)) - (n-supplied (gensym))) - (collect ((temps) - (entries)) - (dotimes (i max) - (temps (gensym))) - + (n-supplied (gensym)) + (temps (make-gensym-list max))) + (collect ((entries)) (do ((eps (optional-dispatch-entry-points fun) (rest eps)) (n min (1+ n))) ((null eps)) (entries `((= ,n-supplied ,n) - (%funcall ,(first eps) ,@(subseq (temps) 0 n))))) - - `(lambda (,n-supplied ,@(temps)) - ;; FIXME: Make sure that INDEX type distinguishes between target - ;; and host. (Probably just make the SB!XC:DEFTYPE different from - ;; CL:DEFTYPE.) + (%funcall ,(first eps) ,@(subseq temps 0 n))))) + `(lambda (,n-supplied ,@temps) + ;; FIXME: Make sure that INDEX type distinguishes between + ;; target and host. (Probably just make the SB!XC:DEFTYPE + ;; different from CL:DEFTYPE.) (declare (type index ,n-supplied)) (cond ,@(if more (butlast (entries)) (entries)) @@ -166,25 +159,25 @@ (n-count (gensym))) `(multiple-value-bind (,n-context ,n-count) (%more-arg-context ,n-supplied ,max) - (%funcall ,more ,@(temps) ,n-context ,n-count)))))) + (%funcall ,more ,@temps ,n-context ,n-count)))))) (t (%argument-count-error ,n-supplied))))))))) -;;; Make an external entry point (XEP) for Fun and return it. We -;;; convert the result of Make-XEP-Lambda in the correct environment, -;;; then associate this lambda with Fun as its XEP. After the +;;; Make an external entry point (XEP) for FUN and return it. We +;;; convert the result of MAKE-XEP-LAMBDA in the correct environment, +;;; then associate this lambda with FUN as its XEP. After the ;;; conversion, we iterate over the function's associated lambdas, ;;; redoing local call analysis so that the XEP calls will get ;;; converted. We also bind *LEXENV* to change the compilation policy ;;; over to the interface policy. ;;; -;;; We set Reanalyze and Reoptimize in the component, just in case we +;;; We set REANALYZE and REOPTIMIZE in the component, just in case we ;;; discover an XEP after the initial local call analyze pass. (defun make-external-entry-point (fun) (declare (type functional fun)) (assert (not (functional-entry-function fun))) (with-ir1-environment (lambda-bind (main-entry fun)) - (let* ((*lexenv* (make-lexenv :cookie (make-interface-cookie *lexenv*))) + (let* ((*lexenv* (make-lexenv :policy (make-interface-policy *lexenv*))) (res (ir1-convert-lambda (make-xep-lambda fun)))) (setf (functional-kind res) :external) (setf (leaf-ever-used res) t) @@ -287,12 +280,13 @@ (values)) -;;; If policy is auspicious, Call is not in an XEP, and we don't seem +;;; If policy is auspicious, CALL is not in an XEP, and we don't seem ;;; to be in an infinite recursive loop, then change the reference to ;;; reference a fresh copy. We return whichever function we decide to ;;; reference. (defun maybe-expand-local-inline (fun ref call) - (if (and (policy call (>= speed space) (>= speed cspeed)) + (if (and (policy call + (and (>= speed space) (>= speed compilation-speed))) (not (eq (functional-kind (node-home-lambda call)) :external)) (not *converting-for-interpreter*) (inline-expansion-ok call)) @@ -424,6 +418,12 @@ ;; but as long as we continue to use that policy, that's the ;; not our biggest problem.:-| When we fix that policy, this ;; should come back into compliance. (So fix that policy!) + ;; ..but.. + ;; FIXME, continued: Except that section "3.2.2.3 Semantic + ;; Constraints" says that if it's within the same file, it's + ;; wrong. And we're in locall.lisp here, so it's probably + ;; (haven't checked this..) a call to something in the same + ;; file. So maybe it deserves a full warning anyway. (compiler-warning "function called with ~R argument~:P, but wants exactly ~R" call-args nargs) @@ -442,17 +442,8 @@ (max-args (optional-dispatch-max-args fun)) (call-args (length (combination-args call)))) (cond ((< call-args min-args) - ;; FIXME: ANSI requires in "3.2.5 Exceptional Situations in the - ;; Compiler" that calling a function with "the wrong number of - ;; arguments" be only a STYLE-ERROR. I think, though, that this - ;; should only apply when the number of arguments is inferred - ;; from a previous definition. If the number of arguments - ;; is DECLAIMed, surely calling with the wrong number is a - ;; real WARNING. As long as SBCL continues to use CMU CL's - ;; non-ANSI DEFUN-is-a-DECLAIM policy, we're in violation here, - ;; but as long as we continue to use that policy, that's the - ;; not our biggest problem.:-| When we fix that policy, this - ;; should come back into compliance. (So fix that policy!) + ;; FIXME: See FIXME note at the previous + ;; wrong-number-of-arguments warnings in this file. (compiler-warning "function called with ~R argument~:P, but wants at least ~R" call-args min-args) @@ -464,17 +455,8 @@ ((optional-dispatch-more-entry fun) (convert-more-call ref call fun)) (t - ;; FIXME: ANSI requires in "3.2.5 Exceptional Situations in the - ;; Compiler" that calling a function with "the wrong number of - ;; arguments" be only a STYLE-ERROR. I think, though, that this - ;; should only apply when the number of arguments is inferred - ;; from a previous definition. If the number of arguments - ;; is DECLAIMed, surely calling with the wrong number is a - ;; real WARNING. As long as SBCL continues to use CMU CL's - ;; non-ANSI DEFUN-is-a-DECLAIM policy, we're in violation here, - ;; but as long as we continue to use that policy, that's the - ;; not our biggest problem.:-| When we fix that policy, this - ;; should come back into compliance. (So fix that policy!) + ;; FIXME: See FIXME note at the previous + ;; wrong-number-of-arguments warnings in this file. (compiler-warning "function called with ~R argument~:P, but wants at most ~R" call-args max-args) @@ -525,11 +507,12 @@ (arglist (optional-dispatch-arglist fun)) (args (combination-args call)) (more (nthcdr max args)) - (flame (policy call (or (> speed brevity) (> space brevity)))) - (loser nil)) - (collect ((temps) - (more-temps) - (ignores) + (flame (policy call (or (> speed inhibit-warnings) + (> space inhibit-warnings)))) + (loser nil) + (temps (make-gensym-list max)) + (more-temps (make-gensym-list (length more)))) + (collect ((ignores) (supplied) (key-vars)) @@ -545,12 +528,6 @@ (setf (basic-combination-kind call) :error) (return-from convert-more-call)))))) - (dotimes (i max) - (temps (gensym "FIXED-ARG-TEMP-"))) - - (dotimes (i (length more)) - (more-temps (gensym "MORE-ARG-TEMP-"))) - (when (optional-dispatch-keyp fun) (when (oddp (length more)) (compiler-warning "function called with odd number of ~ @@ -560,7 +537,7 @@ (return-from convert-more-call)) (do ((key more (cddr key)) - (temp (more-temps) (cddr temp))) + (temp more-temps (cddr temp))) ((null key)) (let ((cont (first key))) (unless (constant-continuation-p cont) @@ -590,7 +567,7 @@ (collect ((call-args)) (do ((var arglist (cdr var)) - (temp (temps) (cdr temp))) + (temp temps (cdr temp))) (()) (let ((info (lambda-var-arg-info (car var)))) (if info @@ -600,7 +577,7 @@ (when (arg-info-supplied-p info) (call-args t))) (:rest - (call-args `(list ,@(more-temps))) + (call-args `(list ,@more-temps)) (return)) (:keyword (return))) @@ -616,7 +593,7 @@ (call-args (not (null temp)))))) (convert-hairy-fun-entry ref call (optional-dispatch-main-entry fun) - (append (temps) (more-temps)) + (append temps more-temps) (ignores) (call-args))))) (values)) @@ -671,13 +648,14 @@ (link-blocks call-block bind-block) next-block))) -;;; Handle the environment semantics of LET conversion. We add the lambda -;;; and its LETs to lets for the Call's home function. We merge the calls for -;;; Fun with the calls for the home function, removing Fun in the process. We -;;; also merge the Entries. +;;; Handle the environment semantics of LET conversion. We add the +;;; lambda and its LETs to lets for the CALL's home function. We merge +;;; the calls for FUN with the calls for the home function, removing +;;; FUN in the process. We also merge the Entries. ;;; ;;; We also unlink the function head from the component head and set -;;; Component-Reanalyze to true to indicate that the DFO should be recomputed. +;;; COMPONENT-REANALYZE to true to indicate that the DFO should be +;;; recomputed. (defun merge-lets (fun call) (declare (type clambda fun) (type basic-combination call)) (let ((component (block-component (node-block call)))) @@ -705,8 +683,7 @@ (setf (lambda-lets fun) ())) (setf (lambda-calls home) - (nunion (lambda-calls fun) - (delete fun (lambda-calls home)))) + (delete fun (nunion (lambda-calls fun) (lambda-calls home)))) (setf (lambda-calls fun) ()) (setf (lambda-entries home) @@ -714,18 +691,19 @@ (setf (lambda-entries fun) ())) (values)) -;;; Handle the value semantics of let conversion. Delete Fun's return node, -;;; and change the control flow to transfer to Next-Block instead. Move all -;;; the uses of the result continuation to Call's Cont. +;;; Handle the value semantics of LET conversion. Delete FUN's return +;;; node, and change the control flow to transfer to NEXT-BLOCK +;;; instead. Move all the uses of the result continuation to CALL's +;;; CONT. ;;; -;;; If the actual continuation is only used by the let call, then we -;;; intersect the type assertion on the dummy continuation with the assertion -;;; for the actual continuation; in all other cases assertions on the dummy -;;; continuation are lost. +;;; If the actual continuation is only used by the LET call, then we +;;; intersect the type assertion on the dummy continuation with the +;;; assertion for the actual continuation; in all other cases +;;; assertions on the dummy continuation are lost. ;;; -;;; We also intersect the derived type of the call with the derived type of -;;; all the dummy continuation's uses. This serves mainly to propagate -;;; TRULY-THE through lets. +;;; We also intersect the derived type of the CALL with the derived +;;; type of all the dummy continuation's uses. This serves mainly to +;;; propagate TRULY-THE through LETs. (defun move-return-uses (fun call next-block) (declare (type clambda fun) (type basic-combination call) (type cblock next-block)) @@ -747,9 +725,9 @@ (substitute-continuation-uses cont result))) (values)) -;;; Change all Cont for all the calls to Fun to be the start continuation -;;; for the bind node. This allows the blocks to be joined if the caller count -;;; ever goes to one. +;;; Change all CONT for all the calls to FUN to be the start +;;; continuation for the bind node. This allows the blocks to be +;;; joined if the caller count ever goes to one. (defun move-let-call-cont (fun) (declare (type clambda fun)) (let ((new-cont (node-prev (lambda-bind fun)))) @@ -759,15 +737,16 @@ (add-continuation-use dest new-cont)))) (values)) -;;; We are converting Fun to be a let when the call is in a non-tail -;;; position. Any previously tail calls in Fun are no longer tail calls, and -;;; must be restored to normal calls which transfer to Next-Block (Fun's -;;; return point.) We can't do this by DO-USES on the RETURN-RESULT, because -;;; the return might have been deleted (if all calls were TR.) +;;; We are converting FUN to be a LET when the call is in a non-tail +;;; position. Any previously tail calls in FUN are no longer tail +;;; calls, and must be restored to normal calls which transfer to +;;; NEXT-BLOCK (FUN's return point.) We can't do this by DO-USES on +;;; the RETURN-RESULT, because the return might have been deleted (if +;;; all calls were TR.) ;;; -;;; The called function might be an assignment in the case where we are -;;; currently converting that function. In steady-state, assignments never -;;; appear in the lambda-calls. +;;; The called function might be an assignment in the case where we +;;; are currently converting that function. In steady-state, +;;; assignments never appear in the lambda-calls. (defun unconvert-tail-calls (fun call next-block) (dolist (called (lambda-calls fun)) (dolist (ref (leaf-refs called)) @@ -789,21 +768,23 @@ (assert (eq called fun)))))))) (values)) -;;; Deal with returning from a let or assignment that we are converting. -;;; FUN is the function we are calling, CALL is a call to FUN, and NEXT-BLOCK -;;; is the return point for a non-tail call, or NULL if call is a tail call. -;;; -;;; If the call is not a tail call, then we must do UNCONVERT-TAIL-CALLS, since -;;; a tail call is a call which returns its value out of the enclosing non-let -;;; function. When call is non-TR, we must convert it back to an ordinary -;;; local call, since the value must be delivered to the receiver of CALL's -;;; value. -;;; -;;; We do different things depending on whether the caller and callee have -;;; returns left: -;;; -- If the callee has no return we just do MOVE-LET-CALL-CONT. Either the -;;; function doesn't return, or all returns are via tail-recursive local -;;; calls. +;;; Deal with returning from a LET or assignment that we are +;;; converting. FUN is the function we are calling, CALL is a call to +;;; FUN, and NEXT-BLOCK is the return point for a non-tail call, or +;;; NULL if call is a tail call. +;;; +;;; If the call is not a tail call, then we must do +;;; UNCONVERT-TAIL-CALLS, since a tail call is a call which returns +;;; its value out of the enclosing non-let function. When call is +;;; non-TR, we must convert it back to an ordinary local call, since +;;; the value must be delivered to the receiver of CALL's value. +;;; +;;; We do different things depending on whether the caller and callee +;;; have returns left: + +;;; -- If the callee has no return we just do MOVE-LET-CALL-CONT. Either +;;; the function doesn't return, or all returns are via tail-recursive +;;; local calls. ;;; -- If CALL is a non-tail call, or if both have returns, then we ;;; delete the callee's return, move its uses to the call's result ;;; continuation, and transfer control to the appropriate return point. @@ -830,11 +811,11 @@ (values)) ;;; Actually do LET conversion. We call subfunctions to do most of the -;;; work. We change the CALL's cont to be the continuation heading the bind -;;; block, and also do REOPTIMIZE-CONTINUATION on the args and Cont so that -;;; let-specific IR1 optimizations get a chance. We blow away any entry for -;;; the function in *FREE-FUNCTIONS* so that nobody will create new reference -;;; to it. +;;; work. We change the CALL's cont to be the continuation heading the +;;; bind block, and also do REOPTIMIZE-CONTINUATION on the args and +;;; Cont so that let-specific IR1 optimizations get a chance. We blow +;;; away any entry for the function in *FREE-FUNCTIONS* so that nobody +;;; will create new reference to it. (defun let-convert (fun call) (declare (type clambda fun) (type basic-combination call)) (let ((next-block (if (node-tail-p call) @@ -852,10 +833,10 @@ (reoptimize-continuation (node-cont call)) (values)) -;;; We also don't convert calls to named functions which appear in the initial -;;; component, delaying this until optimization. This minimizes the likelyhood -;;; that we well let-convert a function which may have references added due to -;;; later local inline expansion +;;; We also don't convert calls to named functions which appear in the +;;; initial component, delaying this until optimization. This +;;; minimizes the likelyhood that we well let-convert a function which +;;; may have references added due to later local inline expansion (defun ok-initial-convert-p (fun) (not (and (leaf-name fun) (eq (component-kind @@ -864,23 +845,24 @@ :initial)))) ;;; This function is called when there is some reason to believe that -;;; the lambda Fun might be converted into a let. This is done after local -;;; call analysis, and also when a reference is deleted. We only convert to a -;;; let when the function is a normal local function, has no XEP, and is -;;; referenced in exactly one local call. Conversion is also inhibited if the -;;; only reference is in a block about to be deleted. We return true if we -;;; converted. -;;; -;;; These rules may seem unnecessarily restrictive, since there are some -;;; cases where we could do the return with a jump that don't satisfy these -;;; requirements. The reason for doing things this way is that it makes the -;;; concept of a let much more useful at the level of IR1 semantics. The -;;; :ASSIGNMENT function kind provides another way to optimize calls to -;;; single-return/multiple call functions. -;;; -;;; We don't attempt to convert calls to functions that have an XEP, since -;;; we might be embarrassed later when we want to convert a newly discovered -;;; local call. Also, see OK-INITIAL-CONVERT-P. +;;; the lambda Fun might be converted into a let. This is done after +;;; local call analysis, and also when a reference is deleted. We only +;;; convert to a let when the function is a normal local function, has +;;; no XEP, and is referenced in exactly one local call. Conversion is +;;; also inhibited if the only reference is in a block about to be +;;; deleted. We return true if we converted. +;;; +;;; These rules may seem unnecessarily restrictive, since there are +;;; some cases where we could do the return with a jump that don't +;;; satisfy these requirements. The reason for doing things this way +;;; is that it makes the concept of a LET much more useful at the +;;; level of IR1 semantics. The :ASSIGNMENT function kind provides +;;; another way to optimize calls to single-return/multiple call +;;; functions. +;;; +;;; We don't attempt to convert calls to functions that have an XEP, +;;; since we might be embarrassed later when we want to convert a +;;; newly discovered local call. Also, see OK-INITIAL-CONVERT-P. (defun maybe-let-convert (fun) (declare (type clambda fun)) (let ((refs (leaf-refs fun))) @@ -907,9 +889,10 @@ ;;;; tail local calls and assignments -;;; Return T if there are no cleanups between Block1 and Block2, or if they -;;; definitely won't generate any cleanup code. Currently we recognize lexical -;;; entry points that are only used locally (if at all). +;;; Return T if there are no cleanups between BLOCK1 and BLOCK2, or if +;;; they definitely won't generate any cleanup code. Currently we +;;; recognize lexical entry points that are only used locally (if at +;;; all). (defun only-harmless-cleanups (block1 block2) (declare (type cblock block1 block2)) (or (eq block1 block2) @@ -923,17 +906,17 @@ (return nil))) (t (return nil))))))) -;;; If a potentially TR local call really is TR, then convert it to jump -;;; directly to the called function. We also call MAYBE-CONVERT-TO-ASSIGNMENT. -;;; The first value is true if we tail-convert. The second is the value of -;;; M-C-T-A. We can switch the succesor (potentially deleting the RETURN node) -;;; unless: +;;; If a potentially TR local call really is TR, then convert it to +;;; jump directly to the called function. We also call +;;; MAYBE-CONVERT-TO-ASSIGNMENT. The first value is true if we +;;; tail-convert. The second is the value of M-C-T-A. We can switch +;;; the succesor (potentially deleting the RETURN node) unless: ;;; -- The call has already been converted. ;;; -- The call isn't TR (some implicit MV PROG1.) -;;; -- The call is in an XEP (thus we might decide to make it non-tail so that -;;; we can use known return inside the component.) -;;; -- There is a change in the cleanup between the call in the return, so we -;;; might need to introduce cleanup code. +;;; -- The call is in an XEP (thus we might decide to make it non-tail +;;; so that we can use known return inside the component.) +;;; -- There is a change in the cleanup between the call in the return, +;;; so we might need to introduce cleanup code. (defun maybe-convert-tail-local-call (call) (declare (type combination call)) (let ((return (continuation-dest (node-cont call)))) @@ -952,25 +935,26 @@ (link-blocks block (node-block (lambda-bind fun))) (values t (maybe-convert-to-assignment fun)))))) -;;; Called when we believe it might make sense to convert Fun to an -;;; assignment. All this function really does is determine when a function -;;; with more than one call can still be combined with the calling function's -;;; environment. We can convert when: +;;; This is called when we believe it might make sense to convert Fun +;;; to an assignment. All this function really does is determine when +;;; a function with more than one call can still be combined with the +;;; calling function's environment. We can convert when: ;;; -- The function is a normal, non-entry function, and -;;; -- Except for one call, all calls must be tail recursive calls in the -;;; called function (i.e. are self-recursive tail calls) +;;; -- Except for one call, all calls must be tail recursive calls +;;; in the called function (i.e. are self-recursive tail calls) ;;; -- OK-INITIAL-CONVERT-P is true. ;;; -;;; There may be one outside call, and it need not be tail-recursive. Since -;;; all tail local calls have already been converted to direct transfers, the -;;; only control semantics needed are to splice in the body at the non-tail -;;; call. If there is no non-tail call, then we need only merge the -;;; environments. Both cases are handled by LET-CONVERT. -;;; -;;; ### It would actually be possible to allow any number of outside calls as -;;; long as they all return to the same place (i.e. have the same conceptual -;;; continuation.) A special case of this would be when all of the outside -;;; calls are tail recursive. +;;; There may be one outside call, and it need not be tail-recursive. +;;; Since all tail local calls have already been converted to direct +;;; transfers, the only control semantics needed are to splice in the +;;; body at the non-tail call. If there is no non-tail call, then we +;;; need only merge the environments. Both cases are handled by +;;; LET-CONVERT. +;;; +;;; ### It would actually be possible to allow any number of outside +;;; calls as long as they all return to the same place (i.e. have the +;;; same conceptual continuation.) A special case of this would be +;;; when all of the outside calls are tail recursive. (defun maybe-convert-to-assignment (fun) (declare (type clambda fun)) (when (and (not (functional-kind fun))