X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Flocall.lisp;h=716afa1d8127597e52bfa56e8baad433b2c7f763;hb=5ec8d0c1c8b7939818b75118b472fac1af554f9a;hp=f08add44b79d834b9572fccc7cc59839fd9d63e6;hpb=c9c0e648c51317ff374851c4fcc740a15d37acae;p=sbcl.git diff --git a/src/compiler/locall.lisp b/src/compiler/locall.lisp index f08add4..716afa1 100644 --- a/src/compiler/locall.lisp +++ b/src/compiler/locall.lisp @@ -21,16 +21,14 @@ (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. +;;; 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. ;;; -;;; We flush all arguments to Call that correspond to unreferenced variables -;;; in Fun. We leave NILs in the Combination-Args so that the remaining args -;;; still match up with their vars. +;;; We flush all arguments to CALL that correspond to unreferenced +;;; variables in FUN. We leave NILs in the COMBINATION-ARGS so that +;;; the remaining args still match up with their vars. ;;; ;;; We also apply the declared variable type assertion to the argument ;;; continuations. @@ -49,17 +47,19 @@ (values)) -;;; This function handles merging the tail sets if Call is potentially -;;; tail-recursive, and is a call to a function with a different TAIL-SET than -;;; Call's Fun. This must be called whenever we alter IR1 so as to place a -;;; local call in what might be a TR context. Note that any call which returns -;;; its value to a RETURN is considered potentially TR, since any implicit -;;; MV-PROG1 might be optimized away. -;;; -;;; We destructively modify the set for the calling function to represent both, -;;; and then change all the functions in callee's set to reference the first. -;;; If we do merge, we reoptimize the RETURN-RESULT continuation to cause -;;; IR1-OPTIMIZE-RETURN to recompute the tail set type. +;;; This function handles merging the tail sets if CALL is potentially +;;; tail-recursive, and is a call to a function with a different +;;; TAIL-SET than CALL's FUN. This must be called whenever we alter +;;; IR1 so as to place a local call in what might be a tail-recursive +;;; context. Note that any call which returns its value to a RETURN is +;;; considered potentially tail-recursive, since any implicit MV-PROG1 +;;; might be optimized away. +;;; +;;; We destructively modify the set for the calling function to +;;; represent both, and then change all the functions in callee's set +;;; to reference the first. If we do merge, we reoptimize the +;;; RETURN-RESULT continuation to cause IR1-OPTIMIZE-RETURN to +;;; recompute the tail set type. (defun merge-tail-sets (call &optional (new-fun (combination-lambda call))) (declare (type basic-combination call) (type clambda new-fun)) (let ((return (continuation-dest (node-cont call)))) @@ -98,30 +98,32 @@ ;;;; 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 @@ -131,7 +133,7 @@ (temps (make-gensym-list (length (lambda-vars fun))))) `(lambda (,n-supplied ,@temps) (declare (type index ,n-supplied)) - ,(if (policy nil (zerop safety)) + ,(if (policy *lexenv* (zerop safety)) `(declare (ignore ,n-supplied)) `(%verify-argument-count ,n-supplied ,nargs)) (%funcall ,fun ,@temps)))) @@ -148,14 +150,14 @@ (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.) + ;; 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)) ,@(when more - `((,(if (zerop min) 't `(>= ,n-supplied ,max)) + `((,(if (zerop min) t `(>= ,n-supplied ,max)) ,(let ((n-context (gensym)) (n-count (gensym))) `(multiple-value-bind (,n-context ,n-count) @@ -164,28 +166,26 @@ (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. +;;; converted. ;;; -;;; 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))) + (aver (not (functional-entry-function fun))) (with-ir1-environment (lambda-bind (main-entry fun)) - (let* ((*lexenv* (make-lexenv :cookie (make-interface-cookie *lexenv*))) - (res (ir1-convert-lambda (make-xep-lambda fun)))) - (setf (functional-kind res) :external) - (setf (leaf-ever-used res) t) - (setf (functional-entry-function res) fun) - (setf (functional-entry-function fun) res) - (setf (component-reanalyze *current-component*) t) - (setf (component-reoptimize *current-component*) t) + (let ((res (ir1-convert-lambda (make-xep-lambda fun)))) + (setf (functional-kind res) :external + (leaf-ever-used res) t + (functional-entry-function res) fun + (functional-entry-function fun) res + (component-reanalyze *current-component*) t + (component-reoptimize *current-component*) t) (etypecase fun (clambda (local-call-analyze-1 fun)) (optional-dispatch @@ -195,12 +195,12 @@ (local-call-analyze-1 (optional-dispatch-more-entry fun))))) res))) -;;; Notice a Ref that is not in a local-call context. If the Ref is +;;; Notice a REF that is not in a local-call context. If the REF is ;;; already to an XEP, then do nothing, otherwise change it to the ;;; XEP, making an XEP if necessary. ;;; -;;; If Ref is to a special :Cleanup or :Escape function, then we treat -;;; it as though it was not an XEP reference (i.e. leave it alone.) +;;; If REF is to a special :CLEANUP or :ESCAPE function, then we treat +;;; it as though it was not an XEP reference (i.e. leave it alone). (defun reference-entry-point (ref) (declare (type ref ref)) (let ((fun (ref-leaf ref))) @@ -209,7 +209,7 @@ (change-ref-leaf ref (or (functional-entry-function fun) (make-external-entry-point fun)))))) -;;; Attempt to convert all references to Fun to local calls. The +;;; Attempt to convert all references to FUN to local calls. The ;;; reference must be the function for a call, and the function ;;; continuation must be used only once, since otherwise we cannot be ;;; sure what function is to be called. The call continuation would be @@ -220,7 +220,7 @@ ;;; function as an entry-point, creating a new XEP if necessary. We ;;; don't try to convert calls that are in error (:ERROR kind.) ;;; -;;; This is broken off from Local-Call-Analyze so that people can +;;; This is broken off from LOCAL-CALL-ANALYZE so that people can ;;; force analysis of newly introduced calls. Note that we don't do ;;; LET conversion here. (defun local-call-analyze-1 (fun) @@ -244,16 +244,16 @@ (values)) -;;; We examine all New-Functions in component, attempting to convert +;;; We examine all NEW-FUNCTIONS in component, attempting to convert ;;; calls into local calls when it is legal. We also attempt to -;;; convert each lambda to a LET. LET conversion is also triggered by +;;; convert each LAMBDA to a LET. LET conversion is also triggered by ;;; deletion of a function reference, but functions that start out ;;; eligible for conversion must be noticed sometime. ;;; ;;; Note that there is a lot of action going on behind the scenes ;;; here, triggered by reference deletion. In particular, the ;;; COMPONENT-LAMBDAS are being hacked to remove newly deleted and let -;;; converted lambdas, so it is important that the lambda is added to +;;; converted LAMBDAs, so it is important that the LAMBDA is added to ;;; the COMPONENT-LAMBDAS when it is. Also, the ;;; COMPONENT-NEW-FUNCTIONS may contain all sorts of drivel, since it ;;; is not updated when we delete functions, etc. Only @@ -281,21 +281,39 @@ (values)) -;;; If policy is auspicious, Call is not in an XEP, and we don't seem +(defun local-call-analyze-until-done (clambdas) + (loop + (let ((did-something nil)) + (dolist (clambda clambdas) + (let* ((component (block-component (node-block (lambda-bind clambda)))) + (*all-components* (list component))) + ;; The original CMU CL code seemed to implicitly assume that + ;; COMPONENT is the only one here. Let's make that explicit. + (aver (= 1 (length (functional-components clambda)))) + (aver (eql component (first (functional-components clambda)))) + (when (component-new-functions component) + (setf did-something t) + (local-call-analyze component)))) + (unless did-something + (return)))) + (values)) + +;;; If policy is auspicious and 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)) (with-ir1-environment call (let* ((*lexenv* (functional-lexenv fun)) (won nil) (res (catch 'local-call-lossage (prog1 - (ir1-convert-lambda (functional-inline-expansion fun)) + (ir1-convert-lambda (functional-inline-expansion + fun)) (setq won t))))) (cond (won (change-ref-leaf ref res) @@ -309,35 +327,36 @@ fun)))) fun)) -;;; Dispatch to the appropriate function to attempt to convert a call. Ref -;;; most be a reference to a FUNCTIONAL. This is called in IR1 optimize as -;;; well as in local call analysis. If the call is is already :Local, we do -;;; nothing. If the call is already scheduled for deletion, also do nothing -;;; (in addition to saving time, this also avoids some problems with optimizing -;;; collections of functions that are partially deleted.) +;;; Dispatch to the appropriate function to attempt to convert a call. +;;; REF must be a reference to a FUNCTIONAL. This is called in IR1 +;;; optimize as well as in local call analysis. If the call is is +;;; already :LOCAL, we do nothing. If the call is already scheduled +;;; for deletion, also do nothing (in addition to saving time, this +;;; also avoids some problems with optimizing collections of functions +;;; that are partially deleted.) ;;; -;;; This is called both before and after FIND-INITIAL-DFO runs. When called -;;; on a :INITIAL component, we don't care whether the caller and callee are in -;;; the same component. Afterward, we must stick with whatever component -;;; division we have chosen. +;;; This is called both before and after FIND-INITIAL-DFO runs. When +;;; called on a :INITIAL component, we don't care whether the caller +;;; and callee are in the same component. Afterward, we must stick +;;; with whatever component division we have chosen. ;;; -;;; Before attempting to convert a call, we see whether the function is -;;; supposed to be inline expanded. Call conversion proceeds as before -;;; after any expansion. +;;; Before attempting to convert a call, we see whether the function +;;; is supposed to be inline expanded. Call conversion proceeds as +;;; before after any expansion. ;;; -;;; We bind *Compiler-Error-Context* to the node for the call so that +;;; We bind *COMPILER-ERROR-CONTEXT* to the node for the call so that ;;; warnings will get the right context. (defun convert-call-if-possible (ref call) (declare (type ref ref) (type basic-combination call)) (let* ((block (node-block call)) (component (block-component block)) (original-fun (ref-leaf ref))) - (assert (functional-p original-fun)) + (aver (functional-p original-fun)) (unless (or (member (basic-combination-kind call) '(:local :error)) (block-delete-p block) (eq (functional-kind (block-home-lambda block)) :deleted) (member (functional-kind original-fun) - '(:top-level-xep :deleted)) + '(:toplevel-xep :deleted)) (not (or (eq (component-kind component) :initial) (eq (block-component (node-block @@ -352,8 +371,8 @@ (rest (leaf-refs original-fun))) (setq fun (maybe-expand-local-inline fun ref call))) - (assert (member (functional-kind fun) - '(nil :escape :cleanup :optional))) + (aver (member (functional-kind fun) + '(nil :escape :cleanup :optional))) (cond ((mv-combination-p call) (convert-mv-call ref call fun)) ((lambda-p fun) @@ -418,6 +437,12 @@ ;; 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) @@ -425,10 +450,11 @@ ;;;; optional, more and keyword calls -;;; Similar to Convert-Lambda-Call, but deals with Optional-Dispatches. If -;;; only fixed args are supplied, then convert a call to the correct entry -;;; point. If keyword args are supplied, then dispatch to a subfunction. We -;;; don't convert calls to functions that have a more (or rest) arg. +;;; This is similar to CONVERT-LAMBDA-CALL, but deals with +;;; OPTIONAL-DISPATCHes. If only fixed args are supplied, then convert +;;; a call to the correct entry point. If &KEY args are supplied, then +;;; dispatch to a subfunction. We don't convert calls to functions +;;; that have a &MORE (or &REST) arg. (defun convert-hairy-call (ref call fun) (declare (type ref ref) (type combination call) (type optional-dispatch fun)) @@ -436,17 +462,8 @@ (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) @@ -458,17 +475,8 @@ ((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) @@ -499,27 +507,29 @@ (dolist (ref (leaf-refs entry)) (convert-call-if-possible ref (continuation-dest (node-cont ref)))))) -;;; Use Convert-Hairy-Fun-Entry to convert a more-arg call to a known -;;; function into a local call to the Main-Entry. +;;; Use CONVERT-HAIRY-FUN-ENTRY to convert a &MORE-arg call to a known +;;; function into a local call to the MAIN-ENTRY. ;;; ;;; First we verify that all keywords are constant and legal. If there ;;; aren't, then we warn the user and don't attempt to convert the call. ;;; -;;; We massage the supplied keyword arguments into the order expected by the -;;; main entry. This is done by binding all the arguments to the keyword call -;;; to variables in the introduced lambda, then passing these values variables -;;; in the correct order when calling the main entry. Unused arguments -;;; (such as the keywords themselves) are discarded simply by not passing them -;;; along. +;;; We massage the supplied &KEY arguments into the order expected +;;; by the main entry. This is done by binding all the arguments to +;;; the keyword call to variables in the introduced lambda, then +;;; passing these values variables in the correct order when calling +;;; the main entry. Unused arguments (such as the keywords themselves) +;;; are discarded simply by not passing them along. ;;; -;;; If there is a rest arg, then we bundle up the args and pass them to LIST. +;;; If there is a &REST arg, then we bundle up the args and pass them +;;; to LIST. (defun convert-more-call (ref call fun) (declare (type ref ref) (type combination call) (type optional-dispatch fun)) (let* ((max (optional-dispatch-max-args fun)) (arglist (optional-dispatch-arglist fun)) (args (combination-args call)) (more (nthcdr max args)) - (flame (policy call (or (> speed brevity) (> space brevity)))) + (flame (policy call (or (> speed inhibit-warnings) + (> space inhibit-warnings)))) (loser nil) (temps (make-gensym-list max)) (more-temps (make-gensym-list (length more)))) @@ -565,7 +575,7 @@ (ignores dummy val) (setq loser name))) (let ((info (lambda-var-arg-info var))) - (when (eq (arg-info-keyword info) name) + (when (eq (arg-info-key info) name) (ignores dummy) (supplied (cons var val)) (return))))))) @@ -611,33 +621,33 @@ ;;;; LET conversion ;;;; -;;;; Converting to a LET has differing significance to various parts of the -;;;; compiler: -;;;; -- The body of a LET is spliced in immediately after the corresponding -;;;; combination node, making the control transfer explicit and allowing -;;;; LETs to be mashed together into a single block. The value of the LET is -;;;; delivered directly to the original continuation for the call, -;;;; eliminating the need to propagate information from the dummy result -;;;; continuation. -;;;; -- As far as IR1 optimization is concerned, it is interesting in that -;;;; there is only one expression that the variable can be bound to, and -;;;; this is easily substitited for. -;;;; -- LETs are interesting to environment analysis and to the back end -;;;; because in most ways a LET can be considered to be "the same function" -;;;; as its home function. -;;;; -- LET conversion has dynamic scope implications, since control transfers -;;;; within the same environment are local. In a local control transfer, -;;;; cleanup code must be emitted to remove dynamic bindings that are no -;;;; longer in effect. - -;;; Set up the control transfer to the called lambda. We split the call -;;; block immediately after the call, and link the head of FUN to the call -;;; block. The successor block after splitting (where we return to) is -;;; returned. -;;; -;;; If the lambda is is a different component than the call, then we call -;;; JOIN-COMPONENTS. This only happens in block compilation before -;;; FIND-INITIAL-DFO. +;;;; Converting to a LET has differing significance to various parts +;;;; of the compiler: +;;;; -- The body of a LET is spliced in immediately after the +;;;; corresponding combination node, making the control transfer +;;;; explicit and allowing LETs to be mashed together into a single +;;;; block. The value of the LET is delivered directly to the +;;;; original continuation for the call,eliminating the need to +;;;; propagate information from the dummy result continuation. +;;;; -- As far as IR1 optimization is concerned, it is interesting in +;;;; that there is only one expression that the variable can be bound +;;;; to, and this is easily substitited for. +;;;; -- LETs are interesting to environment analysis and to the back +;;;; end because in most ways a LET can be considered to be "the +;;;; same function" as its home function. +;;;; -- LET conversion has dynamic scope implications, since control +;;;; transfers within the same environment are local. In a local +;;;; control transfer, cleanup code must be emitted to remove +;;;; dynamic bindings that are no longer in effect. + +;;; Set up the control transfer to the called lambda. We split the +;;; call block immediately after the call, and link the head of FUN to +;;; the call block. The successor block after splitting (where we +;;; return to) is returned. +;;; +;;; If the lambda is is a different component than the call, then we +;;; call JOIN-COMPONENTS. This only happens in block compilation +;;; before FIND-INITIAL-DFO. (defun insert-let-body (fun call) (declare (type clambda fun) (type basic-combination call)) (let* ((call-block (node-block call)) @@ -645,7 +655,7 @@ (component (block-component call-block))) (let ((fun-component (block-component bind-block))) (unless (eq fun-component component) - (assert (eq (component-kind component) :initial)) + (aver (eq (component-kind component) :initial)) (join-components component fun-component))) (let ((*current-component* component)) @@ -653,67 +663,120 @@ ;; FIXME: Use PROPER-LIST-OF-LENGTH-P here, and look for other ;; uses of '=.*length' which could also be converted to use ;; PROPER-LIST-OF-LENGTH-P. - (assert (= (length (block-succ call-block)) 1)) + (aver (= (length (block-succ call-block)) 1)) (let ((next-block (first (block-succ call-block)))) (unlink-blocks call-block next-block) (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. +;;; Remove FUN from the tail set of anything it used to be in the +;;; same set as; but leave FUN with a valid tail set value of +;;; its own, for the benefit of code which might try to pull +;;; something out of it (e.g. return type). +(defun depart-from-tail-set (fun) + ;; Until sbcl-0.pre7.37.flaky5.2, we did + ;; (LET ((TAILS (LAMBDA-TAIL-SET FUN))) + ;; (SETF (TAIL-SET-FUNCTIONS TAILS) + ;; (DELETE FUN (TAIL-SET-FUNCTIONS TAILS)))) + ;; (SETF (LAMBDA-TAIL-SET FUN) NIL) + ;; here. Apparently the idea behind the (SETF .. NIL) was that since + ;; TAIL-SET-FUNCTIONS no longer thinks we're in the tail set, it's + ;; inconsistent, and perhaps unsafe, for us to think we're in the + ;; tail set. Unfortunately.. + ;; + ;; The (SETF .. NIL) caused problems in sbcl-0.pre7.37.flaky5.2 when + ;; I was trying to get Python to emit :EXTERNAL LAMBDAs directly + ;; (instead of only being able to emit funny little :TOPLEVEL stubs + ;; which you called in order to get the address of an external LAMBDA): + ;; the external function was defined in terms of internal function, + ;; which was LET-converted, and then things blew up downstream when + ;; FINALIZE-XEP-DEFINITION tried to find out its DEFINED-TYPE from + ;; the now-NILed-out TAIL-SET. So.. + ;; + ;; To deal with this problem, we no longer NIL out + ;; (LAMBDA-TAIL-SET FUN) here. Instead: + ;; * If we're the only function in TAIL-SET-FUNCTIONS, it should + ;; be safe to leave ourself linked to it, and it to you. + ;; * If there are other functions in TAIL-SET-FUNCTIONS, then we're + ;; afraid of future optimizations on those functions causing + ;; the TAIL-SET object no longer to be valid to describe our + ;; return value. Thus, we delete ourselves from that object; + ;; but we save a newly-allocated tail-set, derived from the old + ;; one, for ourselves, for the use of later code (e.g. + ;; FINALIZE-XEP-DEFINITION) which might want to + ;; know about our return type. + (let* ((old-tail-set (lambda-tail-set fun)) + (old-tail-set-functions (tail-set-functions old-tail-set))) + (unless (= 1 (length old-tail-set-functions)) + (setf (tail-set-functions old-tail-set) + (delete fun old-tail-set-functions)) + (let ((new-tail-set (copy-tail-set old-tail-set))) + (setf (lambda-tail-set fun) new-tail-set + (tail-set-functions new-tail-set) (list fun))))) + ;; The documentation on TAIL-SET-INFO doesn't tell whether it could + ;; remain valid in this case, so we nuke it on the theory that + ;; missing information tends to be less dangerous than incorrect + ;; information. + (setf (tail-set-info (lambda-tail-set fun)) nil)) + +;;; 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)))) (unlink-blocks (component-head component) (node-block (lambda-bind fun))) (setf (component-lambdas component) (delete fun (component-lambdas component))) (setf (component-reanalyze component) t)) (setf (lambda-call-lexenv fun) (node-lexenv call)) - (let ((tails (lambda-tail-set fun))) - (setf (tail-set-functions tails) - (delete fun (tail-set-functions tails)))) - (setf (lambda-tail-set fun) nil) + + (depart-from-tail-set fun) + (let* ((home (node-home-lambda call)) - (home-env (lambda-environment home))) + (home-env (lambda-physenv home))) (push fun (lambda-lets home)) (setf (lambda-home fun) home) - (setf (lambda-environment fun) home-env) + (setf (lambda-physenv fun) home-env) (let ((lets (lambda-lets fun))) (dolist (let lets) (setf (lambda-home let) home) - (setf (lambda-environment let) home-env)) + (setf (lambda-physenv let) home-env)) (setf (lambda-lets home) (nconc lets (lambda-lets home))) (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) (nconc (lambda-entries fun) (lambda-entries home))) (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)) @@ -735,9 +798,9 @@ (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)))) @@ -747,15 +810,16 @@ (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)) @@ -774,29 +838,32 @@ (add-continuation-use this-call cont))) (:deleted) (:assignment - (assert (eq called fun)))))))) + (aver (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. -;;; -- 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. -;;; -- If the callee has a return, but the caller doesn't, then we move the -;;; return to the caller. +;;; 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. +;;; -- If the callee has a return, but the caller doesn't, then we +;;; move the return to the caller. (defun move-return-stuff (fun call next-block) (declare (type clambda fun) (type basic-combination call) (type (or cblock null) next-block)) @@ -811,18 +878,18 @@ (move-return-uses fun call (or next-block (node-block call-return))))) (t - (assert (node-tail-p call)) + (aver (node-tail-p call)) (setf (lambda-return call-fun) return) (setf (return-lambda return) call-fun)))) (move-let-call-cont fun) (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) @@ -840,10 +907,10 @@ (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 @@ -852,23 +919,24 @@ :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))) @@ -878,7 +946,8 @@ (not (functional-entry-function fun))) (let* ((ref-cont (node-cont (first refs))) (dest (continuation-dest ref-cont))) - (when (and (basic-combination-p dest) + (when (and dest + (basic-combination-p dest) (eq (basic-combination-fun dest) ref-cont) (eq (basic-combination-kind dest) :local) (not (block-delete-p (node-block dest))) @@ -895,9 +964,10 @@ ;;;; 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) @@ -911,21 +981,21 @@ (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)))) - (assert (return-p return)) + (aver (return-p return)) (when (and (not (node-tail-p call)) (immediately-used-p (return-result return) call) (not (eq (functional-kind (node-home-lambda call)) @@ -940,25 +1010,26 @@ (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. +;;; 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. +;;; ### 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)) @@ -967,7 +1038,9 @@ (call-fun nil)) (when (and (dolist (ref (leaf-refs fun) t) (let ((dest (continuation-dest (node-cont ref)))) - (when (block-delete-p (node-block dest)) (return nil)) + (when (or (not dest) + (block-delete-p (node-block dest))) + (return nil)) (let ((home (node-home-lambda ref))) (unless (eq home fun) (when call-fun (return nil))