X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fknownfun.lisp;h=bce0879531babce20841b10a21a1321ff39380f2;hb=0f3a5f2e8886d18d0b4f6485c38a42be629422ae;hp=8347fe574606df0f01e44c8605abe8e48938b2b5;hpb=d604a358d8e5eb5587989e0a4f1d31dbe6ac5ffe;p=sbcl.git diff --git a/src/compiler/knownfun.lisp b/src/compiler/knownfun.lisp index 8347fe5..bce0879 100644 --- a/src/compiler/knownfun.lisp +++ b/src/compiler/knownfun.lisp @@ -25,22 +25,29 @@ ;;; breakdown of side effects, since we do very little code motion on ;;; IR1. We are interested in some deeper semantic properties such as ;;; whether it is safe to pass stack closures to. +;;; +;;; FIXME: This whole notion of "bad" explicit attributes is bad for +;;; maintenance. How confident are we that we have no defknowns for functions +;;; with functional arguments that are missing the CALL attribute? Much better +;;; to have NO-CALLS, as it is much less likely to break accidentally. (!def-boolean-attribute ir1 ;; may call functions that are passed as arguments. In order to ;; determine what other effects are present, we must find the ;; effects of all arguments that may be functions. call - ;; may incorporate function or number arguments into the result or - ;; somehow pass them upward. Note that this applies to any argument - ;; that *might* be a function or number, not just the arguments that - ;; always are. - unsafe ;; may fail to return during correct execution. Errors are O.K. + ;; UNUSED, BEWARE OF BITROT. unwind ;; the (default) worst case. Includes all the other bad things, plus ;; any other possible bad thing. If this is present, the above bad ;; attributes will be explicitly present as well. any + ;; all arguments are safe for dynamic extent. + ;; (We used to have an UNSAFE attribute, which was basically the inverse + ;; of this, but it was unused and bitrotted, so when we started making + ;; use of the information we flipped the name and meaning the safe way + ;; around.) + dx-safe ;; may be constant-folded. The function has no side effects, but may ;; be affected by side effects on the arguments. e.g. SVREF, MAPC. ;; Functions that side-effect their arguments are not considered to @@ -61,11 +68,13 @@ ;; in the safe code. If a function MUST signal errors, then it is ;; not unsafely-flushable even if it is movable or foldable. unsafely-flushable + ;; return value is important, and ignoring it is probably a mistake. + ;; Unlike the other attributes, this is used only for style + ;; warnings and has no effect on optimization. + important-result ;; may be moved with impunity. Has no side effects except possibly ;; consing, and is affected only by its arguments. - ;; - ;; Since it is not used now, its distribution in fndb.lisp is - ;; mere random; use with caution. + ;; UNUSED, BEWARE OF BITROT. movable ;; The function is a true predicate likely to be open-coded. Convert ;; any non-conditional uses into (IF T NIL). Not usually @@ -81,7 +90,12 @@ ;; The function does explicit argument type checking, so the ;; declared type should not be asserted when a definition is ;; compiled. - explicit-check) + explicit-check + ;; The function should always be translated by a VOP (i.e. it should + ;; should never be converted into a full call). This is used strictly + ;; as a consistency checking mechanism inside the compiler during IR2 + ;; transformation. + always-translatable) (defstruct (fun-info #-sb-xc-host (:pure t)) ;; boolean attributes of this function. @@ -100,6 +114,9 @@ ;; further optimiz'ns) is backwards from the return convention for ;; transforms. -- WHN 19990917 (optimizer nil :type (or function null)) + ;; a function computing the constant or literal arguments which are + ;; destructively modified by the call. + (destroyed-constant-args nil :type (or function null)) ;; If true, a special-case LTN annotation method that is used in ;; place of the standard type/policy template selection. It may use ;; arbitrary code to choose a template, decide to do a full call, or @@ -114,12 +131,36 @@ ;; If true, the function can stack-allocate the result. The ;; COMBINATION node is passed as an argument. (stack-allocate-result nil :type (or function null)) + ;; If true, the function can add flow-sensitive type information + ;; about the state of the world after its execution. The COMBINATION + ;; node is passed as an argument, along with the current set of + ;; active constraints for the block. The function returns a + ;; sequence of constraints; a constraint is a triplet of a + ;; constraint kind (a symbol, see (defstruct (constraint ...)) in + ;; constraint.lisp) and arguments, either LVARs, LAMBDA-VARs, or + ;; CTYPEs. If any of these arguments is NIL, the constraint is + ;; skipped. This simplifies integration with OK-LVAR-LAMBDA-VAR, + ;; which maps LVARs to LAMBDA-VARs. An optional fourth value in + ;; each constraint flips the meaning of the constraint if it is + ;; non-NIL. + (constraint-propagate nil :type (or function null)) + ;; If true, the function can add flow-sensitive type information + ;; depending on the truthiness of its return value. Returns two + ;; values, a LVAR and a CTYPE. The LVAR is of that CTYPE iff the + ;; function returns true. + ;; It may also return additional third and fourth values. Each is + ;; a sequence of constraints (see CONSTRAINT-PROPAGATE), for the + ;; consequent and alternative branches, respectively. + (constraint-propagate-if nil :type (or function null)) ;; all the templates that could be used to translate this function ;; into IR2, sorted by increasing cost. (templates nil :type list) ;; If non-null, then this function is a unary type predicate for ;; this type. - (predicate-type nil :type (or ctype null))) + (predicate-type nil :type (or ctype null)) + ;; If non-null, the index of the argument which becomes the result + ;; of the function. + (result-arg nil :type (or index null))) (defprinter (fun-info) (attributes :test (not (zerop attributes)) @@ -170,7 +211,8 @@ (eq (transform-important x) important))) (fun-info-transforms info)))) (cond (old - (style-warn "Overwriting ~S" old) + (style-warn 'sb!kernel:redefinition-with-deftransform + :transform old) (setf (transform-function old) fun (transform-note old) note)) (t @@ -183,34 +225,41 @@ ;;; and optimizers. (declaim (ftype (function (list list attributes &key (:derive-type (or function null)) - (:optimizer (or function null))) + (:optimizer (or function null)) + (:destroyed-constant-args (or function null)) + (:result-arg (or index null)) + (:overwrite-fndb-silently boolean)) *) %defknown)) -(defun %defknown (names type attributes &key derive-type optimizer) +(defun %defknown (names type attributes + &key derive-type optimizer destroyed-constant-args result-arg + overwrite-fndb-silently) (let ((ctype (specifier-type type)) (info (make-fun-info :attributes attributes :derive-type derive-type - :optimizer optimizer)) - (target-env *info-environment*)) + :optimizer optimizer + :destroyed-constant-args destroyed-constant-args + :result-arg result-arg))) (dolist (name names) - (let ((old-fun-info (info :function :info name))) - (when old-fun-info - ;; This is handled as an error because it's generally a bad - ;; thing to blow away all the old optimization stuff. It's - ;; also a potential source of sneaky bugs: - ;; DEFKNOWN FOO - ;; DEFTRANSFORM FOO - ;; DEFKNOWN FOO ; possibly hidden inside some macroexpansion - ;; ; Now the DEFTRANSFORM doesn't exist in the target Lisp. - ;; However, it's continuable because it might be useful to do - ;; it when testing new optimization stuff interactively. - (cerror "Go ahead, overwrite it." - "~@" - old-fun-info name))) - (setf (info :function :type name target-env) ctype) - (setf (info :function :where-from name target-env) :declared) - (setf (info :function :kind name target-env) :function) - (setf (info :function :info name target-env) info))) + (unless overwrite-fndb-silently + (let ((old-fun-info (info :function :info name))) + (when old-fun-info + ;; This is handled as an error because it's generally a bad + ;; thing to blow away all the old optimization stuff. It's + ;; also a potential source of sneaky bugs: + ;; DEFKNOWN FOO + ;; DEFTRANSFORM FOO + ;; DEFKNOWN FOO ; possibly hidden inside some macroexpansion + ;; ; Now the DEFTRANSFORM doesn't exist in the target Lisp. + ;; However, it's continuable because it might be useful to do + ;; it when testing new optimization stuff interactively. + (cerror "Go ahead, overwrite it." + "~@" + old-fun-info name)))) + (setf (info :function :type name) ctype) + (setf (info :function :where-from name) :declared) + (setf (info :function :kind name) :function) + (setf (info :function :info name) info))) names) ;;; Return the FUN-INFO for NAME or die trying. Since this is @@ -316,4 +365,44 @@ real-ctype) ctype))))))))) +(defun remove-non-constants-and-nils (fun) + (lambda (list) + (remove-if-not #'lvar-value + (remove-if-not #'constant-lvar-p (funcall fun list))))) + +;;; FIXME: bad name (first because it uses 1-based indexing; second +;;; because it doesn't get the nth constant arguments) +(defun nth-constant-args (&rest indices) + (lambda (list) + (let (result) + (do ((i 1 (1+ i)) + (list list (cdr list)) + (indices indices)) + ((null indices) (nreverse result)) + (when (= i (car indices)) + (when (constant-lvar-p (car list)) + (push (car list) result)) + (setf indices (cdr indices))))))) + +;;; FIXME: a number of the sequence functions not only do not destroy +;;; their argument if it is empty, but also leave it alone if :start +;;; and :end bound a null sequence, or if :count is 0. This test is a +;;; bit complicated to implement, verging on the impossible, but for +;;; extra points (fill #\1 "abc" :start 0 :end 0) should not cause a +;;; warning. +(defun nth-constant-nonempty-sequence-args (&rest indices) + (lambda (list) + (let (result) + (do ((i 1 (1+ i)) + (list list (cdr list)) + (indices indices)) + ((null indices) (nreverse result)) + (when (= i (car indices)) + (when (constant-lvar-p (car list)) + (let ((value (lvar-value (car list)))) + (unless (or (typep value 'null) + (typep value '(vector * 0))) + (push (car list) result)))) + (setf indices (cdr indices))))))) + (/show0 "knownfun.lisp end of file")