X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fir1opt.lisp;h=c22c25ceda55f4a508dc2415e3dcd0a60737f560;hb=4af56c115ef7ec63e06be677f9dfbf8116882e4c;hp=d1d9e68360b8abad9a2f08078c08231878200666;hpb=a71bcb05283105c853b29f77c31d6e9ca869df7d;p=sbcl.git diff --git a/src/compiler/ir1opt.lisp b/src/compiler/ir1opt.lisp index d1d9e68..c22c25c 100644 --- a/src/compiler/ir1opt.lisp +++ b/src/compiler/ir1opt.lisp @@ -42,6 +42,22 @@ ;;; The result value is cached in the LVAR-%DERIVED-TYPE slot. If the ;;; slot is true, just return that value, otherwise recompute and ;;; stash the value there. +(eval-when (:compile-toplevel :execute) + (#+sb-xc-host cl:defmacro + #-sb-xc-host sb!xc:defmacro + lvar-type-using (lvar accessor) + `(let ((uses (lvar-uses ,lvar))) + (cond ((null uses) *empty-type*) + ((listp uses) + (do ((res (,accessor (first uses)) + (values-type-union (,accessor (first current)) + res)) + (current (rest uses) (rest current))) + ((or (null current) (eq res *wild-type*)) + res))) + (t + (,accessor uses)))))) + #!-sb-fluid (declaim (inline lvar-derived-type)) (defun lvar-derived-type (lvar) (declare (type lvar lvar)) @@ -49,18 +65,7 @@ (setf (lvar-%derived-type lvar) (%lvar-derived-type lvar)))) (defun %lvar-derived-type (lvar) - (declare (type lvar lvar)) - (let ((uses (lvar-uses lvar))) - (cond ((null uses) *empty-type*) - ((listp uses) - (do ((res (node-derived-type (first uses)) - (values-type-union (node-derived-type (first current)) - res)) - (current (rest uses) (rest current))) - ((or (null current) (eq res *wild-type*)) - res))) - (t - (node-derived-type uses))))) + (lvar-type-using lvar node-derived-type)) ;;; Return the derived type for LVAR's first value. This is guaranteed ;;; not to be a VALUES or FUNCTION type. @@ -68,6 +73,112 @@ (defun lvar-type (lvar) (single-value-type (lvar-derived-type lvar))) +;;; LVAR-CONSERVATIVE-TYPE +;;; +;;; Certain types refer to the contents of an object, which can +;;; change without type derivation noticing: CONS types and ARRAY +;;; types suffer from this: +;;; +;;; (let ((x (the (cons fixnum fixnum) (cons a b)))) +;;; (setf (car x) c) +;;; (+ (car x) (cdr x))) +;;; +;;; Python doesn't realize that the SETF CAR can change the type of X -- so we +;;; cannot use LVAR-TYPE which gets the derived results. Worse, still, instead +;;; of (SETF CAR) we might have a call to a user-defined function FOO which +;;; does the same -- so there is no way to use the derived information in +;;; general. +;;; +;;; So, the conservative option is to use the derived type if the leaf has +;;; only a single ref -- in which case there cannot be a prior call that +;;; mutates it. Otherwise we use the declared type or punt to the most general +;;; type we know to be correct for sure. +(defun lvar-conservative-type (lvar) + (let ((derived-type (lvar-type lvar)) + (t-type *universal-type*)) + ;; Recompute using NODE-CONSERVATIVE-TYPE instead of derived type if + ;; necessary -- picking off some easy cases up front. + (cond ((or (eq derived-type t-type) + ;; Can't use CSUBTYPEP! + (type= derived-type (specifier-type 'list)) + (type= derived-type (specifier-type 'null))) + derived-type) + ((and (cons-type-p derived-type) + (eq t-type (cons-type-car-type derived-type)) + (eq t-type (cons-type-cdr-type derived-type))) + derived-type) + ((and (array-type-p derived-type) + (or (not (array-type-complexp derived-type)) + (let ((dimensions (array-type-dimensions derived-type))) + (or (eq '* dimensions) + (every (lambda (dim) (eq '* dim)) dimensions))))) + derived-type) + ((type-needs-conservation-p derived-type) + (single-value-type (lvar-type-using lvar node-conservative-type))) + (t + derived-type)))) + +(defun node-conservative-type (node) + (let* ((derived-values-type (node-derived-type node)) + (derived-type (single-value-type derived-values-type))) + (if (ref-p node) + (let ((leaf (ref-leaf node))) + (if (and (basic-var-p leaf) + (cdr (leaf-refs leaf))) + (coerce-to-values + (if (eq :declared (leaf-where-from leaf)) + (leaf-type leaf) + (conservative-type derived-type))) + derived-values-type)) + derived-values-type))) + +(defun conservative-type (type) + (cond ((or (eq type *universal-type*) + (eq type (specifier-type 'list)) + (eq type (specifier-type 'null))) + type) + ((cons-type-p type) + (specifier-type 'cons)) + ((array-type-p type) + (if (array-type-complexp type) + (make-array-type + ;; ADJUST-ARRAY may change dimensions, but rank stays same. + :dimensions + (let ((old (array-type-dimensions type))) + (if (eq '* old) + old + (mapcar (constantly '*) old))) + ;; Complexity cannot change. + :complexp (array-type-complexp type) + ;; Element type cannot change. + :element-type (array-type-element-type type) + :specialized-element-type (array-type-specialized-element-type type)) + ;; Simple arrays cannot change at all. + type)) + (t + ;; If the type contains some CONS types, the conservative type contains all + ;; of them. + (when (types-equal-or-intersect type (specifier-type 'cons)) + (setf type (type-union type (specifier-type 'cons)))) + ;; Similarly for non-simple arrays -- it should be possible to preserve + ;; more information here, but really... + (let ((non-simple-arrays (specifier-type '(and array (not simple-array))))) + (when (types-equal-or-intersect type non-simple-arrays) + (setf type (type-union type non-simple-arrays)))) + type))) + +(defun type-needs-conservation-p (type) + (cond ((eq type *universal-type*) + ;; Excluding T is necessary, because we do want type derivation to + ;; be able to narrow it down in case someone (most like a macro-expansion...) + ;; actually declares something as having type T. + nil) + ((or (cons-type-p type) (and (array-type-p type) (array-type-complexp type))) + ;; Covered by the next case as well, but this is a quick test. + t) + ((types-equal-or-intersect type (specifier-type '(or cons (and array (not simple-array))))) + t))) + ;;; If LVAR is an argument of a function, return a type which the ;;; function checks LVAR for. #!-sb-fluid (declaim (inline lvar-externally-checkable-type)) @@ -1262,19 +1373,27 @@ ;;;; local call optimization -;;; Propagate TYPE to LEAF and its REFS, marking things changed. If -;;; the leaf type is a function type, then just leave it alone, since -;;; TYPE is never going to be more specific than that (and -;;; TYPE-INTERSECTION would choke.) +;;; Propagate TYPE to LEAF and its REFS, marking things changed. +;;; +;;; If the leaf type is a function type, then just leave it alone, since TYPE +;;; is never going to be more specific than that (and TYPE-INTERSECTION would +;;; choke.) +;;; +;;; Also, if the type is one requiring special care don't touch it if the leaf +;;; has multiple references -- otherwise LVAR-CONSERVATIVE-TYPE is screwed. (defun propagate-to-refs (leaf type) (declare (type leaf leaf) (type ctype type)) - (let ((var-type (leaf-type leaf))) - (unless (fun-type-p var-type) + (let ((var-type (leaf-type leaf)) + (refs (leaf-refs leaf))) + (unless (or (fun-type-p var-type) + (and (cdr refs) + (eq :declared (leaf-where-from leaf)) + (type-needs-conservation-p var-type))) (let ((int (type-approx-intersection2 var-type type))) (when (type/= int var-type) (setf (leaf-type leaf) int) (let ((s-int (make-single-value-type int))) - (dolist (ref (leaf-refs leaf)) + (dolist (ref refs) (derive-node-type ref s-int) ;; KLUDGE: LET var substitution (let* ((lvar (node-lvar ref)))