0.7.8.36:
[sbcl.git] / src / compiler / ir1opt.lisp
index 3572089..2dcfc4d 100644 (file)
 (declaim (ftype (function (continuation) ctype) continuation-type))
 (defun continuation-type (cont)
   (single-value-type (continuation-derived-type cont)))
+
+;;; If CONT is an argument of a function, return a type which the
+;;; function checks CONT for.
+#!-sb-fluid (declaim (inline continuation-externally-checkable-type))
+(defun continuation-externally-checkable-type (cont)
+  (or (continuation-%externally-checkable-type cont)
+      (%continuation-%externally-checkable-type cont)))
+(defun %continuation-%externally-checkable-type (cont)
+  (declare (type continuation cont))
+  (let ((dest (continuation-dest cont)))
+      (if (not (and dest (combination-p dest)))
+          ;; TODO: MV-COMBINATION
+          (setf (continuation-%externally-checkable-type cont) *wild-type*)
+          (let* ((fun (combination-fun dest))
+                 (args (combination-args dest))
+                 (fun-type (continuation-type fun)))
+            (if (or (not (fun-type-p fun-type))
+                    ;; FUN-TYPE might be (AND FUNCTION (SATISFIES ...)).
+                    (fun-type-wild-args fun-type))
+                (progn (dolist (arg args)
+                         (setf (continuation-%externally-checkable-type arg)
+                               *wild-type*))
+                       *wild-type*)
+                (let* ((arg-types (append (fun-type-required fun-type)
+                                          (fun-type-optional fun-type)
+                                          (let ((rest (list (or (fun-type-rest fun-type)
+                                                                *wild-type*))))
+                                            (setf (cdr rest) rest)))))
+                  ;; TODO: &KEY
+                  (loop
+                     for arg of-type continuation in args
+                     and type of-type ctype in arg-types
+                     do (setf (continuation-%externally-checkable-type arg)
+                              type))
+                  (continuation-%externally-checkable-type cont)))))))
 \f
 ;;;; interface routines used by optimizers
 
         (let ((info (combination-kind node)))
           (when (fun-info-p info)
             (let ((attr (fun-info-attributes info)))
-              (when (and (ir1-attributep attr flushable)
+              (when (and (not (ir1-attributep attr call))
                          ;; ### For now, don't delete potentially
                          ;; flushable calls when they have the CALL
                          ;; attribute. Someday we should look at the
                          ;; functional args to determine if they have
                          ;; any side effects.
-                         (not (ir1-attributep attr call)))
+                          (if (policy node (= safety 3))
+                              (and (ir1-attributep attr flushable)
+                                   (every (lambda (arg)
+                                            ;; FIXME: when bug 203
+                                            ;; will be fixed, remove
+                                            ;; this check
+                                            (member (continuation-type-check arg)
+                                                    '(nil :deleted)))
+                                          (basic-combination-args node))
+                                   (valid-fun-use node
+                                                  (info :function :type
+                                                        (leaf-source-name (ref-leaf (continuation-use (basic-combination-fun node)))))
+                                                  :result-test #'always-subtypep
+                                                  :lossage-fun nil
+                                                  :unwinnage-fun nil))
+                              (ir1-attributep attr unsafely-flushable)))
                 (flush-dest (combination-fun node))
                 (dolist (arg (combination-args node))
                   (flush-dest arg))
           (new-block (continuation-starts-block new-cont)))
       (link-node-to-previous-continuation new-node new-cont)
       (setf (continuation-dest new-cont) new-node)
+      (setf (continuation-%externally-checkable-type new-cont) nil)
       (add-continuation-use new-node dummy-cont)
       (setf (block-last new-block) new-node)
 
                 (continuation-use (basic-combination-fun call))
                 call))
               ((not leaf))
-              ((or (info :function :source-transform (leaf-source-name leaf))
-                   (and info
-                        (ir1-attributep (fun-info-attributes info)
-                                        predicate)
-                        (let ((dest (continuation-dest (node-cont call))))
-                          (and dest (not (if-p dest))))))
-               (when (and (leaf-has-source-name-p leaf)
-                          ;; FIXME: This SYMBOLP is part of a literal
-                          ;; translation of a test in the old CMU CL
-                          ;; source, and it's not quite clear what
-                          ;; the old source meant. Did it mean "has a
-                          ;; valid name"? Or did it mean "is an
-                          ;; ordinary function name, not a SETF
-                          ;; function"? Either way, the old CMU CL
-                          ;; code probably didn't deal with SETF
-                          ;; functions correctly, and neither does
-                          ;; this new SBCL code, and that should be fixed.
-                          (symbolp (leaf-source-name leaf)))
-                 (let ((dummies (make-gensym-list (length
-                                                   (combination-args call)))))
-                   (transform-call call
-                                   `(lambda ,dummies
-                                      (,(leaf-source-name leaf)
-                                       ,@dummies))
-                                   (leaf-source-name leaf))))))))))
+              ((and (leaf-has-source-name-p leaf)
+                     (or (info :function :source-transform (leaf-source-name leaf))
+                         (and info
+                              (ir1-attributep (fun-info-attributes info)
+                                              predicate)
+                              (let ((dest (continuation-dest (node-cont call))))
+                                (and dest (not (if-p dest)))))))
+                ;; FIXME: This SYMBOLP is part of a literal
+                ;; translation of a test in the old CMU CL
+                ;; source, and it's not quite clear what
+                ;; the old source meant. Did it mean "has a
+                ;; valid name"? Or did it mean "is an
+                ;; ordinary function name, not a SETF
+                ;; function"? Either way, the old CMU CL
+                ;; code probably didn't deal with SETF
+                ;; functions correctly, and neither does
+                ;; this new SBCL code, and that should be fixed.
+               (when (symbolp (leaf-source-name leaf))
+                  (let ((dummies (make-gensym-list
+                                  (length (combination-args call)))))
+                    (transform-call call
+                                    `(lambda ,dummies
+                                      (,(leaf-source-name leaf)
+                                       ,@dummies))
+                                    (leaf-source-name leaf))))))))))
   (values))
 \f
 ;;;; known function optimization
   (let ((args (mapcar #'continuation-value (combination-args call)))
        (fun-name (combination-fun-source-name call)))
     (multiple-value-bind (values win)
-       (careful-call fun-name args call "constant folding")
+       (careful-call fun-name
+                     args
+                     call
+                     ;; Note: CMU CL had COMPILER-WARN here, and that
+                     ;; seems more natural, but it's probably not.
+                     ;;
+                     ;; It's especially not while bug 173 exists:
+                     ;; Expressions like
+                     ;;   (COND (END
+                     ;;          (UNLESS (OR UNSAFE? (<= END SIZE)))
+                     ;;            ...))
+                     ;; can cause constant-folding TYPE-ERRORs (in
+                     ;; #'<=) when END can be proved to be NIL, even
+                     ;; though the code is perfectly legal and safe
+                     ;; because a NIL value of END means that the
+                     ;; #'<= will never be executed.
+                     ;;
+                     ;; Moreover, even without bug 173,
+                     ;; quite-possibly-valid code like
+                     ;;   (COND ((NONINLINED-PREDICATE END)
+                     ;;          (UNLESS (<= END SIZE))
+                     ;;            ...))
+                     ;; (where NONINLINED-PREDICATE is something the
+                     ;; compiler can't do at compile time, but which
+                     ;; turns out to make the #'<= expression
+                     ;; unreachable when END=NIL) could cause errors
+                     ;; when the compiler tries to constant-fold (<=
+                     ;; END SIZE).
+                     ;;
+                     ;; So, with or without bug 173, it'd be 
+                     ;; unnecessarily evil to do a full
+                     ;; COMPILER-WARNING (and thus return FAILURE-P=T
+                     ;; from COMPILE-FILE) for legal code, so we we
+                     ;; use a wimpier COMPILE-STYLE-WARNING instead.
+                     #'compiler-style-warn
+                     "constant folding")
       (if (not win)
          (setf (combination-kind call) :error)
          (let ((dummies (make-gensym-list (length args))))
   (derive-node-type node (continuation-type (set-value node)))
   (values))
 
-;;; Return true if the value of Ref will always be the same (and is
+;;; Return true if the value of REF will always be the same (and is
 ;;; thus legal to substitute.)
 (defun constant-reference-p (ref)
   (declare (type ref ref))
        (flush-dest (combination-fun use))
        (let ((fun-cont (basic-combination-fun call)))
          (setf (continuation-dest fun-cont) use)
-         (setf (combination-fun use) fun-cont))
+          (setf (combination-fun use) fun-cont)
+         (setf (continuation-%externally-checkable-type fun-cont) nil))
        (setf (combination-kind use) :local)
        (setf (functional-kind fun) :let)
        (flush-dest (first (basic-combination-args call)))
       (setf (combination-kind node) :full)
       (let ((args (combination-args use)))
        (dolist (arg args)
-         (setf (continuation-dest arg) node))
+         (setf (continuation-dest arg) node)
+          (setf (continuation-%externally-checkable-type arg) nil))
        (setf (combination-args use) nil)
        (flush-dest list)
        (setf (combination-args node) args))