Optimize CONCATENATE transform.
[sbcl.git] / src / compiler / seqtran.lisp
index 7a4e0fe..40040ab 100644 (file)
 
 (defun mapfoo-transform (fn arglists accumulate take-car)
   (collect ((do-clauses)
-           (args-to-fn)
-           (tests))
+            (args-to-fn)
+            (tests))
     (let ((n-first (gensym)))
       (dolist (a (if accumulate
-                    arglists
-                    `(,n-first ,@(rest arglists))))
-       (let ((v (gensym)))
-         (do-clauses `(,v ,a (cdr ,v)))
-         (tests `(endp ,v))
-         (args-to-fn (if take-car `(car ,v) v))))
+                     arglists
+                     `(,n-first ,@(rest arglists))))
+        (let ((v (gensym)))
+          (do-clauses `(,v ,a (cdr ,v)))
+          (tests `(endp ,v))
+          (args-to-fn (if take-car `(car ,v) v))))
 
       (let* ((fn-sym (gensym))  ; for ONCE-ONLY-ish purposes
-            (call `(funcall ,fn-sym . ,(args-to-fn)))
-            (endtest `(or ,@(tests))))
-       (ecase accumulate
-         (:nconc
-          (let ((temp (gensym))
-                (map-result (gensym)))
-            `(let ((,fn-sym ,fn)
-                   (,map-result (list nil)))
-               (do-anonymous ((,temp ,map-result) . ,(do-clauses))
-                             (,endtest (cdr ,map-result))
-                 (setq ,temp (last (nconc ,temp ,call)))))))
-         (:list
-          (let ((temp (gensym))
-                (map-result (gensym)))
-            `(let ((,fn-sym ,fn)
-                   (,map-result (list nil)))
-               (do-anonymous ((,temp ,map-result) . ,(do-clauses))
-                             (,endtest (truly-the list (cdr ,map-result)))
-                 (rplacd ,temp (setq ,temp (list ,call)))))))
-         ((nil)
-          `(let ((,fn-sym ,fn)
-                 (,n-first ,(first arglists)))
-             (do-anonymous ,(do-clauses)
-                           (,endtest (truly-the list ,n-first))
-                            ,call))))))))
+             (call `(%funcall ,fn-sym . ,(args-to-fn)))
+             (endtest `(or ,@(tests))))
+
+        `(let ((,fn-sym (%coerce-callable-to-fun ,fn)))
+           ,(ecase accumulate
+             (:nconc
+              (let ((temp (gensym))
+                    (map-result (gensym)))
+                `(let ((,map-result (list nil)))
+                   (do-anonymous ((,temp ,map-result) . ,(do-clauses))
+                     (,endtest (cdr ,map-result))
+                     (setq ,temp (last (nconc ,temp ,call)))))))
+             (:list
+              (let ((temp (gensym))
+                    (map-result (gensym)))
+                `(let ((,map-result (list nil)))
+                   (do-anonymous ((,temp ,map-result) . ,(do-clauses))
+                     (,endtest (truly-the list (cdr ,map-result)))
+                     (rplacd ,temp (setq ,temp (list ,call)))))))
+             ((nil)
+              `(let ((,n-first ,(first arglists)))
+                 (do-anonymous ,(do-clauses)
+                   (,endtest (truly-the list ,n-first))
+                   ,call)))))))))
 
 (define-source-transform mapc (function list &rest more-lists)
   (mapfoo-transform function (cons list more-lists) nil t))
 ;;; TRULY-THE for the most specific type we can determine.
 (deftransform map ((result-type-arg fun seq &rest seqs) * * :node node)
   (let* ((seq-names (make-gensym-list (1+ (length seqs))))
-        (bare `(%map result-type-arg fun ,@seq-names))
-        (constant-result-type-arg-p (constant-continuation-p result-type-arg))
-        ;; what we know about the type of the result. (Note that the
-        ;; "result type" argument is not necessarily the type of the
-        ;; result, since NIL means the result has NULL type.)
-        (result-type (if (not constant-result-type-arg-p)
-                         'consed-sequence
-                         (let ((result-type-arg-value
-                                (continuation-value result-type-arg)))
-                           (if (null result-type-arg-value)
-                               'null
-                               result-type-arg-value)))))
+         (bare `(%map result-type-arg fun ,@seq-names))
+         (constant-result-type-arg-p (constant-lvar-p result-type-arg))
+         ;; what we know about the type of the result. (Note that the
+         ;; "result type" argument is not necessarily the type of the
+         ;; result, since NIL means the result has NULL type.)
+         (result-type (if (not constant-result-type-arg-p)
+                          'consed-sequence
+                          (let ((result-type-arg-value
+                                 (lvar-value result-type-arg)))
+                            (if (null result-type-arg-value)
+                                'null
+                                result-type-arg-value)))))
     `(lambda (result-type-arg fun ,@seq-names)
        (truly-the ,result-type
-        ,(cond ((policy node (< safety 3))
-                ;; ANSI requires the length-related type check only
-                ;; when the SAFETY quality is 3... in other cases, we
-                ;; skip it, because it could be expensive.
-                bare)
-               ((not constant-result-type-arg-p)
-                `(sequence-of-checked-length-given-type ,bare
-                                                        result-type-arg))
-               (t
-                (let ((result-ctype (ir1-transform-specifier-type
-                                     result-type)))
-                  (if (array-type-p result-ctype)
-                      (let ((dims (array-type-dimensions result-ctype)))
-                        (unless (and (listp dims) (= (length dims) 1))
-                          (give-up-ir1-transform "invalid sequence type"))
-                        (let ((dim (first dims)))
-                          (if (eq dim '*)
-                              bare
-                              `(vector-of-checked-length-given-length ,bare
-                                                                      ,dim))))
-                      ;; FIXME: this is wrong, as not all subtypes of
-                      ;; VECTOR are ARRAY-TYPEs [consider, for
-                      ;; example, (OR (VECTOR T 3) (VECTOR T
-                      ;; 4))]. However, it's difficult to see what we
-                      ;; should put here... maybe we should
-                      ;; GIVE-UP-IR1-TRANSFORM if the type is a
-                      ;; subtype of VECTOR but not an ARRAY-TYPE?
-                      bare))))))))
+         ,(cond ((policy node (< safety 3))
+                 ;; ANSI requires the length-related type check only
+                 ;; when the SAFETY quality is 3... in other cases, we
+                 ;; skip it, because it could be expensive.
+                 bare)
+                ((not constant-result-type-arg-p)
+                 `(sequence-of-checked-length-given-type ,bare
+                                                         result-type-arg))
+                (t
+                 (let ((result-ctype (ir1-transform-specifier-type
+                                      result-type)))
+                   (if (array-type-p result-ctype)
+                       (let ((dims (array-type-dimensions result-ctype)))
+                         (unless (and (listp dims) (= (length dims) 1))
+                           (give-up-ir1-transform "invalid sequence type"))
+                         (let ((dim (first dims)))
+                           (if (eq dim '*)
+                               bare
+                               `(vector-of-checked-length-given-length ,bare
+                                                                       ,dim))))
+                       ;; FIXME: this is wrong, as not all subtypes of
+                       ;; VECTOR are ARRAY-TYPEs [consider, for
+                       ;; example, (OR (VECTOR T 3) (VECTOR T
+                       ;; 4))]. However, it's difficult to see what we
+                       ;; should put here... maybe we should
+                       ;; GIVE-UP-IR1-TRANSFORM if the type is a
+                       ;; subtype of VECTOR but not an ARRAY-TYPE?
+                       bare))))))))
 
 ;;; Return a DO loop, mapping a function FUN to elements of
-;;; sequences. SEQS is a list of continuations, SEQ-NAMES - list of
-;;; variables, bound to sequences, INTO - a variable, which is used in
+;;; sequences. SEQS is a list of lvars, SEQ-NAMES - list of variables,
+;;; bound to sequences, INTO - a variable, which is used in
 ;;; MAP-INTO. RESULT and BODY are forms, which can use variables
 ;;; FUNCALL-RESULT, containing the result of application of FUN, and
 ;;; INDEX, containing the current position in sequences.
-(defun build-sequence-iterator (seqs seq-names &key result into body)
+(defun build-sequence-iterator (seqs seq-names &key result into body fast)
   (declare (type list seqs seq-names)
            (type symbol into))
   (collect ((bindings)
-           (declarations)
+            (declarations)
             (vector-lengths)
             (tests)
-            (places))
+            (places)
+            (around))
     (let ((found-vector-p nil))
       (flet ((process-vector (length)
                (unless found-vector-p
                  (bindings `(index 0 (1+ index)))
                  (declarations `(type index index)))
                (vector-lengths length)))
-        (loop for seq of-type continuation in seqs
+        (loop for seq of-type lvar in seqs
            for seq-name in seq-names
-           for type = (continuation-type seq)
+           for type = (lvar-type seq)
            do (cond ((csubtypep type (specifier-type 'list))
-                    (with-unique-names (index)
+                     (with-unique-names (index)
                        (bindings `(,index ,seq-name (cdr ,index)))
                        (declarations `(type list ,index))
                        (places `(car ,index))
                        (tests `(endp ,index))))
-                    ((csubtypep type (specifier-type 'vector))
+                    ((or (csubtypep type (specifier-type '(simple-array * 1)))
+                         (and (not fast)
+                              (csubtypep type (specifier-type 'vector))))
                      (process-vector `(length ,seq-name))
-                     (places `(aref ,seq-name index)))
+                     (places `(locally (declare (optimize (insert-array-bounds-checks 0)))
+                                (aref ,seq-name index))))
+                    ((csubtypep type (specifier-type 'vector))
+                     (let ((data  (gensym "DATA"))
+                           (start (gensym "START"))
+                           (end   (gensym "END")))
+                       (around `(with-array-data ((,data ,seq-name)
+                                                  (,start)
+                                                  (,end (length ,seq-name)))))
+                       (process-vector `(- ,end ,start))
+                       (places `(locally (declare (optimize (insert-array-bounds-checks 0)))
+                                  (aref ,data (truly-the index (+ index ,start)))))))
                     (t
                      (give-up-ir1-transform
                       "can't determine sequence argument type"))))
           (process-vector `(array-dimension ,into 0))))
       (when found-vector-p
         (bindings `(length (min ,@(vector-lengths))))
-        (tests `(= index length)))
-      `(do (,@(bindings))
-           ((or ,@(tests)) ,result)
-         (declare ,@(declarations))
-         (let ((funcall-result (funcall fun ,@(places))))
-           (declare (ignorable funcall-result))
-           ,body)))))
+        (tests `(>= index length)))
+      (let ((body `(do (,@(bindings))
+                       ((or ,@(tests)) ,result)
+                     (declare ,@(declarations))
+                     (let ((funcall-result (funcall fun ,@(places))))
+                       (declare (ignorable funcall-result))
+                       ,body))))
+        (if (around)
+            (reduce (lambda (wrap body) (append wrap (list body)))
+                    (around)
+                    :from-end t
+                    :initial-value body)
+            body)))))
 
 ;;; Try to compile %MAP efficiently when we can determine sequence
 ;;; argument types at compile time.
 ;;; the reader, because the code is complicated enough already and I
 ;;; don't happen to need that functionality right now. -- WHN 20000410
 (deftransform %map ((result-type fun seq &rest seqs) * *
-                   :policy (>= speed space))
+                    :node node :policy (>= speed space))
   "open code"
-  (unless (constant-continuation-p result-type)
+  (unless (constant-lvar-p result-type)
     (give-up-ir1-transform "RESULT-TYPE argument not constant"))
   (labels ( ;; 1-valued SUBTYPEP, fails unless second value of SUBTYPEP is true
-          (fn-1subtypep (fn x y)
-            (multiple-value-bind (subtype-p valid-p) (funcall fn x y)
-              (if valid-p
-                  subtype-p
-                  (give-up-ir1-transform
-                   "can't analyze sequence type relationship"))))
-          (1subtypep (x y) (fn-1subtypep #'sb!xc:subtypep x y)))
-    (let* ((result-type-value (continuation-value result-type))
-          (result-supertype (cond ((null result-type-value) 'null)
-                                  ((1subtypep result-type-value 'vector)
-                                   'vector)
-                                  ((1subtypep result-type-value 'list)
-                                   'list)
-                                  (t
-                                   (give-up-ir1-transform
-                                    "can't determine result type")))))
+           (fn-1subtypep (fn x y)
+             (multiple-value-bind (subtype-p valid-p) (funcall fn x y)
+               (if valid-p
+                   subtype-p
+                   (give-up-ir1-transform
+                    "can't analyze sequence type relationship"))))
+           (1subtypep (x y) (fn-1subtypep #'sb!xc:subtypep x y)))
+    (let* ((result-type-value (lvar-value result-type))
+           (result-supertype (cond ((null result-type-value) 'null)
+                                   ((1subtypep result-type-value 'vector)
+                                    'vector)
+                                   ((1subtypep result-type-value 'list)
+                                    'list)
+                                   (t
+                                    (give-up-ir1-transform
+                                     "result type unsuitable")))))
       (cond ((and result-type-value (null seqs))
-            ;; The consing arity-1 cases can be implemented
-            ;; reasonably efficiently as function calls, and the cost
-            ;; of consing should be significantly larger than
-            ;; function call overhead, so we always compile these
-            ;; cases as full calls regardless of speed-versus-space
-            ;; optimization policy.
-            (cond ((subtypep result-type-value 'list)
-                   '(%map-to-list-arity-1 fun seq))
-                  ( ;; (This one can be inefficient due to COERCE, but
-                   ;; the current open-coded implementation has the
-                   ;; same problem.)
-                   (subtypep result-type-value 'vector)
-                   `(coerce (%map-to-simple-vector-arity-1 fun seq)
-                            ',result-type-value))
-                  (t (bug "impossible (?) sequence type"))))
-           (t
-            (let* ((seqs (cons seq seqs))
-                   (seq-args (make-gensym-list (length seqs))))
-              (multiple-value-bind (push-dacc result)
-                  (ecase result-supertype
-                    (null (values nil nil))
-                    (list (values `(push funcall-result acc)
+             ;; The consing arity-1 cases can be implemented
+             ;; reasonably efficiently as function calls, and the cost
+             ;; of consing should be significantly larger than
+             ;; function call overhead, so we always compile these
+             ;; cases as full calls regardless of speed-versus-space
+             ;; optimization policy.
+             (cond ((subtypep result-type-value 'list)
+                    '(%map-to-list-arity-1 fun seq))
+                   ( ;; (This one can be inefficient due to COERCE, but
+                    ;; the current open-coded implementation has the
+                    ;; same problem.)
+                    (subtypep result-type-value 'vector)
+                    `(coerce (%map-to-simple-vector-arity-1 fun seq)
+                             ',result-type-value))
+                   (t (bug "impossible (?) sequence type"))))
+            (t
+             (let* ((seqs (cons seq seqs))
+                    (seq-args (make-gensym-list (length seqs))))
+               (multiple-value-bind (push-dacc result)
+                   (ecase result-supertype
+                     (null (values nil nil))
+                     (list (values `(push funcall-result acc)
                                    `(nreverse acc)))
-                    (vector (values `(push funcall-result acc)
-                                    `(coerce (nreverse acc)
-                                             ',result-type-value))))
-                ;; (We use the same idiom, of returning a LAMBDA from
-                ;; DEFTRANSFORM, as is used in the DEFTRANSFORMs for
-                ;; FUNCALL and ALIEN-FUNCALL, and for the same
-                ;; reason: we need to get the runtime values of each
-                ;; of the &REST vars.)
-                `(lambda (result-type fun ,@seq-args)
-                   (declare (ignore result-type))
+                     (vector (values `(push funcall-result acc)
+                                     `(coerce (nreverse acc)
+                                              ',result-type-value))))
+                 ;; (We use the same idiom, of returning a LAMBDA from
+                 ;; DEFTRANSFORM, as is used in the DEFTRANSFORMs for
+                 ;; FUNCALL and ALIEN-FUNCALL, and for the same
+                 ;; reason: we need to get the runtime values of each
+                 ;; of the &REST vars.)
+                 `(lambda (result-type fun ,@seq-args)
+                    (declare (ignore result-type))
                     (let ((fun (%coerce-callable-to-fun fun))
                           (acc nil))
                       (declare (type list acc))
                       ,(build-sequence-iterator
                         seqs seq-args
                         :result result
-                        :body push-dacc))))))))))
+                        :body push-dacc
+                        :fast (policy node (> speed space))))))))))))
 
 ;;; MAP-INTO
 (deftransform map-into ((result fun &rest seqs)
                         (vector * &rest *)
-                        *)
+                        * :node node)
   "open code"
   (let ((seqs-names (mapcar (lambda (x)
                               (declare (ignore x))
                               (gensym))
                             seqs)))
     `(lambda (result fun ,@seqs-names)
-       ,(build-sequence-iterator
-         seqs seqs-names
-         :result '(when (array-has-fill-pointer-p result)
-                   (setf (fill-pointer result) index))
-         :into 'result
-         :body '(setf (aref result index) funcall-result))
+       ,(if (and (policy node (> speed space))
+                 (not (csubtypep (lvar-type result)
+                                 (specifier-type '(simple-array * 1)))))
+            (let ((data  (gensym "DATA"))
+                  (start (gensym "START"))
+                  (end   (gensym "END")))
+              `(with-array-data ((,data result)
+                                 (,start)
+                                 (,end))
+                 (declare (ignore ,end))
+                 ,(build-sequence-iterator
+                   seqs seqs-names
+                   :result '(when (array-has-fill-pointer-p result)
+                             (setf (fill-pointer result) index))
+                   :into 'result
+                   :body `(locally (declare (optimize (insert-array-bounds-checks 0)))
+                           (setf (aref ,data (truly-the index (+ index ,start)))
+                                 funcall-result))
+                   :fast t)))
+            (build-sequence-iterator
+             seqs seqs-names
+             :result '(when (array-has-fill-pointer-p result)
+                       (setf (fill-pointer result) index))
+             :into 'result
+             :body '(locally (declare (optimize (insert-array-bounds-checks 0)))
+                     (setf (aref result index) funcall-result))))
        result)))
 
 \f
   '(nth i s))
 
 (deftransform %setelt ((s i v) ((simple-array * (*)) * *) *)
-  '(%aset s i v))
+  '(setf (aref s i) v))
 
 (deftransform %setelt ((s i v) (list * *) * :policy (< safety 3))
   '(setf (car (nthcdr i s)) v))
 
 (deftransform %check-vector-sequence-bounds ((vector start end)
-                                            (vector * *) *
-                                            :node node)
-  (if (policy node (< safety speed))
+                                             (vector * *) *
+                                             :node node)
+  (if (policy node (= 0 insert-array-bounds-checks))
       '(or end (length vector))
       '(let ((length (length vector)))
-       (if (<= 0 start (or end length) length)
-           (or end length)
-           (sb!impl::signal-bounding-indices-bad-error vector start end)))))
-
-(macrolet ((def (name)
-             `(deftransform ,name ((e l &key (test #'eql)) * *
-                                  :node node)
-                (unless (constant-continuation-p l)
-                  (give-up-ir1-transform))
-
-                (let ((val (continuation-value l)))
-                  (unless (policy node
-                                  (or (= speed 3)
-                                      (and (>= speed space)
-                                           (<= (length val) 5))))
-                    (give-up-ir1-transform))
-
-                  (labels ((frob (els)
-                             (if els
-                                 `(if (funcall test e ',(car els))
-                                      ',els
-                                      ,(frob (cdr els)))
-                                 nil)))
-                    (frob val))))))
-  (def member)
-  (def memq))
-
-;;; FIXME: We have rewritten the original code that used DOLIST to this
-;;; more natural MACROLET.  However, the original code suggested that when
-;;; this was done, a few bytes could be saved by a call to a shared
-;;; function.  This remains to be done.
-(macrolet ((def (fun eq-fun)
-             `(deftransform ,fun ((item list &key test) (t list &rest t) *)
-                "convert to EQ test"
-                ;; FIXME: The scope of this transformation could be
-                ;; widened somewhat, letting it work whenever the test is
-                ;; 'EQL and we know from the type of ITEM that it #'EQ
-                ;; works like #'EQL on it. (E.g. types FIXNUM, CHARACTER,
-                ;; and SYMBOL.)
-                ;;   If TEST is EQ, apply transform, else
-                ;;   if test is not EQL, then give up on transform, else
-                ;;   if ITEM is not a NUMBER or is a FIXNUM, apply
-                ;;   transform, else give up on transform.
-                (cond (test
-                       (unless (continuation-fun-is test '(eq))
-                         (give-up-ir1-transform)))
-                      ((types-equal-or-intersect (continuation-type item)
-                                                 (specifier-type 'number))
-                       (give-up-ir1-transform "Item might be a number.")))
-                `(,',eq-fun item list))))
-  (def delete delq)
-  (def assoc assq)
-  (def member memq))
+         (if (<= 0 start (or end length) length)
+             (or end length)
+             (sequence-bounding-indices-bad-error vector start end)))))
+
+(def!type eq-comparable-type ()
+  '(or fixnum (not number)))
+
+;;; True if EQL comparisons involving type can be simplified to EQ.
+(defun eq-comparable-type-p (type)
+  (csubtypep type (specifier-type 'eq-comparable-type)))
+
+(defun specialized-list-seek-function-name (function-name key-functions &optional variant)
+  (or (find-symbol (with-output-to-string (s)
+                     ;; Write "%NAME-FUN1-FUN2-FUN3", etc. Not only is
+                     ;; this ever so slightly faster then FORMAT, this
+                     ;; way we are also proof against *PRINT-CASE*
+                     ;; frobbing and such.
+                     (write-char #\% s)
+                     (write-string (symbol-name function-name) s)
+                     (dolist (f key-functions)
+                       (write-char #\- s)
+                       (write-string (symbol-name f) s))
+                     (when variant
+                       (write-char #\- s)
+                       (write-string (symbol-name variant) s)))
+                   (load-time-value (find-package "SB!KERNEL")))
+      (bug "Unknown list item seek transform: name=~S, key-functions=~S variant=~S"
+           function-name key-functions variant)))
+
+(defparameter *list-open-code-limit* 128)
+
+(defun transform-list-item-seek (name item list key test test-not node)
+  (when (and test test-not)
+    (abort-ir1-transform "Both ~S and ~S supplied to ~S." :test :test-not name))
+  ;; If TEST is EQL, drop it.
+  (when (and test (lvar-fun-is test '(eql)))
+    (setf test nil))
+  ;; Ditto for KEY IDENTITY.
+  (when (and key (lvar-fun-is key '(identity)))
+    (setf key nil))
+  ;; Key can legally be NIL, but if it's NIL for sure we pretend it's
+  ;; not there at all. If it might be NIL, make up a form to that
+  ;; ensures it is a function.
+  (multiple-value-bind (key key-form)
+      (when key
+        (let ((key-type (lvar-type key))
+              (null-type (specifier-type 'null)))
+          (cond ((csubtypep key-type null-type)
+                 (values nil nil))
+                ((csubtypep null-type key-type)
+                 (values key '(if key
+                               (%coerce-callable-to-fun key)
+                               #'identity)))
+                (t
+                 (values key (ensure-lvar-fun-form key 'key))))))
+    (let* ((c-test (cond ((and test (lvar-fun-is test '(eq)))
+                          (setf test nil)
+                          'eq)
+                         ((and (not test) (not test-not))
+                          (when (eq-comparable-type-p (lvar-type item))
+                            'eq))))
+           (funs (delete nil (list (when key (list key 'key))
+                                   (when test (list test 'test))
+                                   (when test-not (list test-not 'test-not)))))
+           (target-expr (if key '(%funcall key target) 'target))
+           (test-expr (cond (test `(%funcall test item ,target-expr))
+                            (test-not `(not (%funcall test-not item ,target-expr)))
+                            (c-test `(,c-test item ,target-expr))
+                            (t `(eql item ,target-expr)))))
+      (labels ((open-code (tail)
+                 (when tail
+                   `(if (let ((this ',(car tail)))
+                          ,(ecase name
+                                  ((assoc rassoc)
+                                   (let ((cxx (if (eq name 'assoc) 'car 'cdr)))
+                                     `(and this (let ((target (,cxx this)))
+                                                  ,test-expr))))
+                                  (member
+                                   `(let ((target this))
+                                      ,test-expr))))
+                        ',(ecase name
+                                 ((assoc rassoc) (car tail))
+                                 (member tail))
+                        ,(open-code (cdr tail)))))
+               (ensure-fun (args)
+                 (if (eq 'key (second args))
+                     key-form
+                     (apply #'ensure-lvar-fun-form args))))
+        (let* ((cp (constant-lvar-p list))
+               (c-list (when cp (lvar-value list))))
+          (cond ((and cp c-list (member name '(assoc rassoc member))
+                      (policy node (>= speed space))
+                      (not (nthcdr *list-open-code-limit* c-list)))
+                 `(let ,(mapcar (lambda (fun) `(,(second fun) ,(ensure-fun fun))) funs)
+                    ,(open-code c-list)))
+                ((and cp (not c-list))
+                 ;; constant nil list
+                 (if (eq name 'adjoin)
+                     '(list item)
+                     nil))
+                (t
+                 ;; specialized out-of-line version
+                 `(,(specialized-list-seek-function-name name (mapcar #'second funs) c-test)
+                    item list ,@(mapcar #'ensure-fun funs)))))))))
+
+(defun transform-list-pred-seek (name pred list key node)
+  ;; If KEY is IDENTITY, drop it.
+  (when (and key (lvar-fun-is key '(identity)))
+    (setf key nil))
+  ;; Key can legally be NIL, but if it's NIL for sure we pretend it's
+  ;; not there at all. If it might be NIL, make up a form to that
+  ;; ensures it is a function.
+  (multiple-value-bind (key key-form)
+      (when key
+        (let ((key-type (lvar-type key))
+              (null-type (specifier-type 'null)))
+          (cond ((csubtypep key-type null-type)
+                 (values nil nil))
+                ((csubtypep null-type key-type)
+                 (values key '(if key
+                               (%coerce-callable-to-fun key)
+                               #'identity)))
+                (t
+                 (values key (ensure-lvar-fun-form key 'key))))))
+    (let ((test-expr `(%funcall pred ,(if key '(%funcall key target) 'target)))
+          (pred-expr (ensure-lvar-fun-form pred 'pred)))
+      (when (member name '(member-if-not assoc-if-not rassoc-if-not))
+        (setf test-expr `(not ,test-expr)))
+      (labels ((open-code (tail)
+                 (when tail
+                   `(if (let ((this ',(car tail)))
+                          ,(ecase name
+                                  ((assoc-if assoc-if-not rassoc-if rassoc-if-not)
+                                   (let ((cxx (if (member name '(assoc-if assoc-if-not)) 'car 'cdr)))
+                                     `(and this (let ((target (,cxx this)))
+                                                  ,test-expr))))
+                                  ((member-if member-if-not)
+                                   `(let ((target this))
+                                      ,test-expr))))
+                        ',(ecase name
+                                 ((assoc-if assoc-if-not rassoc-if rassoc-if-not)
+                                  (car tail))
+                                 ((member-if member-if-not)
+                                  tail))
+                        ,(open-code (cdr tail))))))
+        (let* ((cp (constant-lvar-p list))
+               (c-list (when cp (lvar-value list))))
+          (cond ((and cp c-list (policy node (>= speed space))
+                      (not (nthcdr *list-open-code-limit* c-list)))
+                 `(let ((pred ,pred-expr)
+                        ,@(when key `((key ,key-form))))
+                    ,(open-code c-list)))
+                ((and cp (not c-list))
+                 ;; constant nil list -- nothing to find!
+                 nil)
+                (t
+                 ;; specialized out-of-line version
+                 `(,(specialized-list-seek-function-name name (when key '(key)))
+                    ,pred-expr list ,@(when key (list key-form))))))))))
+
+(macrolet ((def (name &optional if/if-not)
+             (let ((basic (symbolicate "%" name))
+                   (basic-eq (symbolicate "%" name "-EQ"))
+                   (basic-key (symbolicate "%" name "-KEY"))
+                   (basic-key-eq (symbolicate "%" name "-KEY-EQ")))
+               `(progn
+                  (deftransform ,name ((item list &key key test test-not) * * :node node)
+                    (transform-list-item-seek ',name item list key test test-not node))
+                  (deftransform ,basic ((item list) (eq-comparable-type t))
+                    `(,',basic-eq item list))
+                  (deftransform ,basic-key ((item list) (eq-comparable-type t))
+                    `(,',basic-key-eq item list))
+                  ,@(when if/if-not
+                          (let ((if-name (symbolicate name "-IF"))
+                                (if-not-name (symbolicate name "-IF-NOT")))
+                            `((deftransform ,if-name ((pred list &key key) * * :node node)
+                                (transform-list-pred-seek ',if-name pred list key node))
+                              (deftransform ,if-not-name ((pred list &key key) * * :node node)
+                                (transform-list-pred-seek ',if-not-name pred list key node)))))))))
+  (def adjoin)
+  (def assoc  t)
+  (def member t)
+  (def rassoc t))
+
+(deftransform memq ((item list) (t (constant-arg list)))
+  (labels ((rec (tail)
+             (if tail
+                 `(if (eq item ',(car tail))
+                      ',tail
+                      ,(rec (cdr tail)))
+                 nil)))
+    (rec (lvar-value list))))
+
+;;; A similar transform used to apply to MEMBER and ASSOC, but since
+;;; TRANSFORM-LIST-ITEM-SEEK now takes care of them those transform
+;;; would never fire, and (%MEMBER-TEST ITEM LIST #'EQ) should be
+;;; almost as fast as MEMQ.
+(deftransform delete ((item list &key test) (t list &rest t) *)
+  "convert to EQ test"
+  (let ((type (lvar-type item)))
+    (unless (or (and test (lvar-fun-is test '(eq)))
+                (and (eq-comparable-type-p type)
+                     (or (not test) (lvar-fun-is test '(eql)))))
+      (give-up-ir1-transform)))
+  `(delq item list))
 
 (deftransform delete-if ((pred list) (t list))
   "open code"
   '(do ((x list (cdr x))
-       (splice '()))
+        (splice '()))
        ((endp x) list)
      (cond ((funcall pred (car x))
-           (if (null splice)
-               (setq list (cdr x))
-               (rplacd splice (cdr x))))
-          (T (setq splice x)))))
-
-(deftransform fill ((seq item &key (start 0) (end (length seq)))
-                   (vector t &key (:start t) (:end index))
-                   *
-                   :policy (> speed space))
-  "open code"
-  (let ((element-type (upgraded-element-type-specifier-or-give-up seq)))
-    (values 
-     `(with-array-data ((data seq)
-                       (start start)
-                       (end end))
-       (declare (type (simple-array ,element-type 1) data))
-       (declare (type fixnum start end))
-       (do ((i start (1+ i)))
-          ((= i end) seq)
-        (declare (type index i))
-        ;; WITH-ARRAY-DATA did our range checks once and for all, so
-        ;; it'd be wasteful to check again on every AREF...
-        (declare (optimize (safety 0))) 
-        (setf (aref data i) item)))
-     ;; ... though we still need to check that the new element can fit
-     ;; into the vector in safe code. -- CSR, 2002-07-05
-     `((declare (type ,element-type item))))))
-\f
-;;;; utilities
-
-;;; Return true if CONT's only use is a non-NOTINLINE reference to a
-;;; global function with one of the specified NAMES.
-(defun continuation-fun-is (cont names)
-  (declare (type continuation cont) (list names))
-  (let ((use (continuation-use cont)))
-    (and (ref-p use)
-        (let ((leaf (ref-leaf use)))
-          (and (global-var-p leaf)
-               (eq (global-var-kind leaf) :global-function)
-               (not (null (member (leaf-source-name leaf) names
-                                  :test #'equal))))))))
-
-;;; If CONT is a constant continuation, the return the constant value.
-;;; If it is null, then return default, otherwise quietly give up the
-;;; IR1 transform.
-;;;
-;;; ### Probably should take an ARG and flame using the NAME.
-(defun constant-value-or-lose (cont &optional default)
-  (declare (type (or continuation null) cont))
-  (cond ((not cont) default)
-       ((constant-continuation-p cont)
-        (continuation-value cont))
-       (t
-        (give-up-ir1-transform))))
-
-;;; FIXME: Why is this code commented out? (Why *was* it commented
-;;; out? We inherited this situation from cmucl-2.4.8, with no
-;;; explanation.) Should we just delete this code?
-#|
-;;; This is a frob whose job it is to make it easier to pass around
-;;; the arguments to IR1 transforms. It bundles together the name of
-;;; the argument (which should be referenced in any expansion), and
-;;; the continuation for that argument (or NIL if unsupplied.)
-(defstruct (arg (:constructor %make-arg (name cont))
-               (:copier nil))
-  (name nil :type symbol)
-  (cont nil :type (or continuation null)))
-(defmacro make-arg (name)
-  `(%make-arg ',name ,name))
-
-;;; If Arg is null or its CONT is null, then return Default, otherwise
-;;; return Arg's NAME.
-(defun default-arg (arg default)
-  (declare (type (or arg null) arg))
-  (if (and arg (arg-cont arg))
-      (arg-name arg)
-      default))
-
-;;; If Arg is null or has no CONT, return the default. Otherwise, Arg's
-;;; CONT must be a constant continuation whose value we return. If not, we
-;;; give up.
-(defun arg-constant-value (arg default)
-  (declare (type (or arg null) arg))
-  (if (and arg (arg-cont arg))
-      (let ((cont (arg-cont arg)))
-       (unless (constant-continuation-p cont)
-         (give-up-ir1-transform "Argument is not constant: ~S."
-                                (arg-name arg)))
-       (continuation-value from-end))
-      default))
-
-;;; If Arg is a constant and is EQL to X, then return T, otherwise NIL. If
-;;; Arg is NIL or its CONT is NIL, then compare to the default.
-(defun arg-eql (arg default x)
-  (declare (type (or arg null) x))
-  (if (and arg (arg-cont arg))
-      (let ((cont (arg-cont arg)))
-       (and (constant-continuation-p cont)
-            (eql (continuation-value cont) x)))
-      (eql default x)))
-
-(defstruct (iterator (:copier nil))
-  ;; The kind of iterator.
-  (kind nil (member :normal :result))
-  ;; A list of LET* bindings to create the initial state.
-  (binds nil :type list)
-  ;; A list of declarations for Binds.
-  (decls nil :type list)
-  ;; A form that returns the current value. This may be set with SETF to set
-  ;; the current value.
-  (current (error "Must specify CURRENT."))
-  ;; In a :NORMAL iterator, a form that tests whether there is a current value.
-  (done nil)
-  ;; In a :RESULT iterator, a form that truncates the result at the current
-  ;; position and returns it.
-  (result nil)
-  ;; A form that returns the initial total number of values. The result is
-  ;; undefined after NEXT has been evaluated.
-  (length (error "Must specify LENGTH."))
-  ;; A form that advances the state to the next value. It is an error to call
-  ;; this when the iterator is Done.
-  (next (error "Must specify NEXT.")))
-
-;;; Type of an index var that can go negative (in the from-end case.)
-(deftype neg-index ()
-  `(integer -1 ,most-positive-fixnum))
-
-;;; Return an ITERATOR structure describing how to iterate over an arbitrary
-;;; sequence. Sequence is a variable bound to the sequence, and Type is the
-;;; type of the sequence. If true, INDEX is a variable that should be bound to
-;;; the index of the current element in the sequence.
-;;;
-;;; If we can't tell whether the sequence is a list or a vector, or whether
-;;; the iteration is forward or backward, then GIVE-UP.
-(defun make-sequence-iterator (sequence type &key start end from-end index)
-  (declare (symbol sequence) (type ctype type)
-          (type (or arg null) start end from-end)
-          (type (or symbol null) index))
-  (let ((from-end (arg-constant-value from-end nil)))
-    (cond ((csubtypep type (specifier-type 'vector))
-          (let* ((n-stop (gensym))
-                 (n-idx (or index (gensym)))
-                 (start (default-arg 0 start))
-                 (end (default-arg `(length ,sequence) end)))
-            (make-iterator
-             :kind :normal
-             :binds `((,n-idx ,(if from-end `(1- ,end) ,start))
-                      (,n-stop ,(if from-end `(1- ,start) ,end)))
-             :decls `((type neg-index ,n-idx ,n-stop))
-             :current `(aref ,sequence ,n-idx)
-             :done `(,(if from-end '<= '>=) ,n-idx ,n-stop)
-             :next `(setq ,n-idx
-                          ,(if from-end `(1- ,n-idx) `(1+ ,n-idx)))
-             :length (if from-end
-                         `(- ,n-idx ,n-stop)
-                         `(- ,n-stop ,n-idx)))))
-         ((csubtypep type (specifier-type 'list))
-          (let* ((n-stop (if (and end (not from-end)) (gensym) nil))
-                 (n-current (gensym))
-                 (start-p (not (arg-eql start 0 0)))
-                 (end-p (not (arg-eql end nil nil)))
-                 (start (default-arg start 0))
-                 (end (default-arg end nil)))
-            (make-iterator
-             :binds `((,n-current
-                       ,(if from-end
-                            (if (or start-p end-p)
-                                `(nreverse (subseq ,sequence ,start
-                                                   ,@(when end `(,end))))
-                                `(reverse ,sequence))
-                            (if start-p
-                                `(nthcdr ,start ,sequence)
-                                sequence)))
-                      ,@(when n-stop
-                          `((,n-stop (nthcdr (the index
-                                                  (- ,end ,start))
-                                             ,n-current))))
-                      ,@(when index
-                          `((,index ,(if from-end `(1- ,end) start)))))
-             :kind :normal
-             :decls `((list ,n-current ,n-end)
-                      ,@(when index `((type neg-index ,index))))
-             :current `(car ,n-current)
-             :done `(eq ,n-current ,n-stop)
-             :length `(- ,(or end `(length ,sequence)) ,start)
-             :next `(progn
-                      (setq ,n-current (cdr ,n-current))
-                      ,@(when index
-                          `((setq ,n-idx
-                                  ,(if from-end
-                                       `(1- ,index)
-                                       `(1+ ,index)))))))))
-         (t
-          (give-up-ir1-transform
-           "can't tell whether sequence is a list or a vector")))))
-
-;;; Make an iterator used for constructing result sequences. Name is a
-;;; variable to be bound to the result sequence. Type is the type of result
-;;; sequence to make. Length is an expression to be evaluated to get the
-;;; maximum length of the result (not evaluated in list case.)
-(defun make-result-sequence-iterator (name type length)
-  (declare (symbol name) (type ctype type))
-
-;;; Define each NAME as a local macro that will call the value of the
-;;; function arg with the given arguments. If the argument isn't known to be a
-;;; function, give them an efficiency note and reference a coerced version.
-(defmacro coerce-funs (specs &body body)
-  #!+sb-doc
-  "COERCE-FUNCTIONS ({(Name Fun-Arg Default)}*) Form*"
-  (collect ((binds)
-           (defs))
-    (dolist (spec specs)
-      `(let ((body (progn ,@body))
-            (n-fun (arg-name ,(second spec)))
-            (fun-cont (arg-cont ,(second spec))))
-        (cond ((not fun-cont)
-               `(macrolet ((,',(first spec) (&rest args)
-                            `(,',',(third spec) ,@args)))
-                  ,body))
-              ((not (csubtypep (continuation-type fun-cont)
-                               (specifier-type 'function)))
-               (when (policy *compiler-error-context*
-                             (> speed inhibit-warnings))
-                 (compiler-notify
-                  "~S may not be a function, so must coerce at run-time."
-                  n-fun))
-               (once-only ((n-fun `(if (functionp ,n-fun)
-                                       ,n-fun
-                                       (symbol-function ,n-fun))))
-                 `(macrolet ((,',(first spec) (&rest args)
-                              `(funcall ,',n-fun ,@args)))
-                    ,body)))
-              (t
-               `(macrolet ((,',(first spec) (&rest args)
-                             `(funcall ,',n-fun ,@args)))
-                  ,body)))))))
-
-;;; Wrap code around the result of the body to define Name as a local macro
-;;; that returns true when its arguments satisfy the test according to the Args
-;;; Test and Test-Not. If both Test and Test-Not are supplied, abort the
-;;; transform.
-(defmacro with-sequence-test ((name test test-not) &body body)
-  `(let ((not-p (arg-cont ,test-not)))
-     (when (and (arg-cont ,test) not-p)
-       (abort-ir1-transform "Both ~S and ~S were supplied."
-                           (arg-name ,test)
-                           (arg-name ,test-not)))
-     (coerce-funs ((,name (if not-p ,test-not ,test) eql))
-       ,@body)))
-|#
+            (if (null splice)
+                (setq list (cdr x))
+                (rplacd splice (cdr x))))
+           (t (setq splice x)))))
+
+(deftransform fill ((seq item &key (start 0) (end nil))
+                    (list t &key (:start t) (:end t)))
+  '(list-fill* seq item start end))
+
+(deftransform fill ((seq item &key (start 0) (end nil))
+                    (vector t &key (:start t) (:end t))
+                    *
+                    :node node)
+  (let* ((type (lvar-type seq))
+         (element-ctype (array-type-upgraded-element-type type))
+         (element-type (type-specifier element-ctype))
+         (saetp (unless (eq *wild-type* element-ctype)
+                  (find-saetp-by-ctype element-ctype))))
+    (cond ((eq *wild-type* element-ctype)
+           (delay-ir1-transform node :constraint)
+           `(vector-fill* seq item start end))
+          ((and saetp (sb!vm::valid-bit-bash-saetp-p saetp))
+           (let* ((n-bits (sb!vm:saetp-n-bits saetp))
+                  (basher-name (format nil "UB~D-BASH-FILL" n-bits))
+                  (basher (or (find-symbol basher-name
+                                           (load-time-value (find-package :sb!kernel)))
+                              (abort-ir1-transform
+                               "Unknown fill basher, please report to sbcl-devel: ~A"
+                               basher-name)))
+                  (kind (cond ((sb!vm:saetp-fixnum-p saetp) :tagged)
+                              ((member element-type '(character base-char)) :char)
+                              ((eq element-type 'single-float) :single-float)
+                              #!+#.(cl:if (cl:= 64 sb!vm:n-word-bits) '(and) '(or))
+                              ((eq element-type 'double-float) :double-float)
+                              #!+#.(cl:if (cl:= 64 sb!vm:n-word-bits) '(and) '(or))
+                              ((equal element-type '(complex single-float))
+                               :complex-single-float)
+                              (t
+                               (aver (integer-type-p element-ctype))
+                               :bits)))
+                  ;; BASH-VALUE is a word that we can repeatedly smash
+                  ;; on the array: for less-than-word sized elements it
+                  ;; contains multiple copies of the fill item.
+                  (bash-value
+                   (if (constant-lvar-p item)
+                       (let ((tmp (lvar-value item)))
+                         (unless (ctypep tmp element-ctype)
+                           (abort-ir1-transform "~S is not ~S" tmp element-type))
+                         (let* ((bits
+                                 (ldb (byte n-bits 0)
+                                      (ecase kind
+                                        (:tagged
+                                         (ash tmp sb!vm:n-fixnum-tag-bits))
+                                        (:char
+                                         (char-code tmp))
+                                        (:bits
+                                         tmp)
+                                        (:single-float
+                                         (single-float-bits tmp))
+                                        #!+#.(cl:if (cl:= 64 sb!vm:n-word-bits) '(and) '(or))
+                                        (:double-float
+                                         (logior (ash (double-float-high-bits tmp) 32)
+                                                 (double-float-low-bits tmp)))
+                                        #!+#.(cl:if (cl:= 64 sb!vm:n-word-bits) '(and) '(or))
+                                        (:complex-single-float
+                                         (logior (ash (single-float-bits (imagpart tmp)) 32)
+                                                 (ldb (byte 32 0)
+                                                      (single-float-bits (realpart tmp))))))))
+                                (res bits))
+                           (loop for i of-type sb!vm:word from n-bits by n-bits
+                                 until (= i sb!vm:n-word-bits)
+                                 do (setf res (ldb (byte sb!vm:n-word-bits 0)
+                                                   (logior res (ash bits i)))))
+                           res))
+                       (progn
+                         (delay-ir1-transform node :constraint)
+                        `(let* ((bits (ldb (byte ,n-bits 0)
+                                           ,(ecase kind
+                                                   (:tagged
+                                                    `(ash item ,sb!vm:n-fixnum-tag-bits))
+                                                   (:char
+                                                    `(char-code item))
+                                                   (:bits
+                                                    `item)
+                                                   (:single-float
+                                                    `(single-float-bits item))
+                                                   #!+#.(cl:if (cl:= 64 sb!vm:n-word-bits) '(and) '(or))
+                                                   (:double-float
+                                                    `(logior (ash (double-float-high-bits item) 32)
+                                                             (double-float-low-bits item)))
+                                                   #!+#.(cl:if (cl:= 64 sb!vm:n-word-bits) '(and) '(or))
+                                                   (:complex-single-float
+                                                    `(logior (ash (single-float-bits (imagpart item)) 32)
+                                                             (ldb (byte 32 0)
+                                                                  (single-float-bits (realpart item))))))))
+                                (res bits))
+                           (declare (type sb!vm:word res))
+                           ,@(unless (= sb!vm:n-word-bits n-bits)
+                                     `((loop for i of-type sb!vm:word from ,n-bits by ,n-bits
+                                             until (= i sb!vm:n-word-bits)
+                                             do (setf res
+                                                      (ldb (byte ,sb!vm:n-word-bits 0)
+                                                           (logior res (ash bits (truly-the (integer 0 ,(- sb!vm:n-word-bits n-bits)) i))))))))
+                           res)))))
+             (values
+              ;; KLUDGE: WITH-ARRAY data in its full glory is going to mess up
+              ;; dynamic-extent for MAKE-ARRAY :INITIAL-ELEMENT initialization.
+              (if (csubtypep (lvar-type seq) (specifier-type '(simple-array * (*))))
+                  `(let* ((len (length seq))
+                          (end (or end len))
+                          (bound (1+ end)))
+                     ;; Minor abuse %CHECK-BOUND for bounds checking.
+                     ;; (- END START) may still end up negative, but
+                     ;; the basher handle that.
+                     (,basher ,bash-value seq
+                              (%check-bound seq bound start)
+                              (- (if end (%check-bound seq bound end) len)
+                                 start)))
+               `(with-array-data ((data seq)
+                                  (start start)
+                                  (end end)
+                                  :check-fill-pointer t)
+                  (declare (type (simple-array ,element-type 1) data))
+                  (declare (type index start end))
+                  (declare (optimize (safety 0) (speed 3)))
+                  (,basher ,bash-value data start (- end start))
+                  seq))
+              `((declare (type ,element-type item))))))
+          ((policy node (> speed space))
+           (values
+            `(with-array-data ((data seq)
+                               (start start)
+                               (end end)
+                               :check-fill-pointer t)
+               (declare (type (simple-array ,element-type 1) data))
+               (declare (type index start end))
+               ;; WITH-ARRAY-DATA did our range checks once and for all, so
+               ;; it'd be wasteful to check again on every AREF...
+               (declare (optimize (safety 0) (speed 3)))
+               (do ((i start (1+ i)))
+                   ((= i end) seq)
+                 (declare (type index i))
+                 (setf (aref data i) item)))
+            ;; ... though we still need to check that the new element can fit
+            ;; into the vector in safe code. -- CSR, 2002-07-05
+            `((declare (type ,element-type item)))))
+          ((csubtypep type (specifier-type 'string))
+           '(string-fill* seq item start end))
+          (t
+           '(vector-fill* seq item start end)))))
+
+(deftransform fill ((seq item &key (start 0) (end nil))
+                    ((and sequence (not vector) (not list)) t &key (:start t) (:end t)))
+  `(sb!sequence:fill seq item
+                     :start start
+                     :end (%check-generic-sequence-bounds seq start end)))
 \f
 ;;;; hairy sequence transforms
 
 ;;; FIXME: no hairy sequence transforms in SBCL?
+;;;
+;;; There used to be a bunch of commented out code about here,
+;;; containing the (apparent) beginning of hairy sequence transform
+;;; infrastructure. People interested in implementing better sequence
+;;; transforms might want to look at it for inspiration, even though
+;;; the actual code is ancient CMUCL -- and hence bitrotted. The code
+;;; was deleted in 1.0.7.23.
 \f
 ;;;; string operations
 
 ;;; must be SIMPLE-BASE-STRINGs.
 (macrolet ((def (name lessp equalp)
              `(deftransform ,name ((string1 string2 start1 end1 start2 end2)
-                                    (simple-base-string simple-base-string t t t t) *)
+                                   (simple-base-string simple-base-string t t t t) *)
                 `(let* ((end1 (if (not end1) (length string1) end1))
                         (end2 (if (not end2) (length string2) end2))
                         (index (sb!impl::%sp-string-compare
                                 string1 start1 end1 string2 start2 end2)))
                   (if index
-                      (cond ((= index ,(if ',lessp 'end1 'end2)) index)
-                            ((= index ,(if ',lessp 'end2 'end1)) nil)
+                      (cond ((= index end1)
+                             ,(if ',lessp 'index nil))
+                            ((= (+ index (- start2 start1)) end2)
+                             ,(if ',lessp nil 'index))
                             ((,(if ',lessp 'char< 'char>)
                                (schar string1 index)
                                (schar string2
                                                  (+ index
                                                     (truly-the fixnum
                                                                (- start2
-                                                                 start1))))))
+                                                                  start1))))))
                              index)
                             (t nil))
                       ,(if ',equalp 'end1 nil))))))
   (def string/=* identity))
 
 \f
-;;;; string-only transforms for sequence functions
-;;;;
-;;;; Note: CMU CL had more of these, including transforms for
-;;;; functions which cons. In SBCL, we've gotten rid of most of the
-;;;; transforms for functions which cons, since our GC overhead is
-;;;; sufficiently large that it doesn't seem worth it to try to
-;;;; economize on function call overhead or on the overhead of runtime
-;;;; type dispatch in AREF. The exception is CONCATENATE, since
-;;;; a full call to CONCATENATE would have to look up the sequence
-;;;; type, which can be really slow.
-;;;;
-;;;; FIXME: It would be nicer for these transforms to work for any
-;;;; calls when all arguments are vectors with the same element type,
-;;;; rather than restricting them to STRINGs only.
+;;;; transforms for sequence functions
 
-;;; Moved here from generic/vm-tran.lisp to satisfy clisp
-;;;
-;;; FIXME: Add a comment telling whether this holds for all vectors
-;;; or only for vectors based on simple arrays (non-adjustable, etc.).
+;;; Moved here from generic/vm-tran.lisp to satisfy clisp.  Only applies
+;;; to vectors based on simple arrays.
 (def!constant vector-data-bit-offset
   (* sb!vm:vector-data-offset sb!vm:n-word-bits))
 
-(deftransform replace ((string1 string2 &key (start1 0) (start2 0)
-                               end1 end2)
-                      (simple-base-string simple-base-string &rest t)
-                      *
-                      ;; FIXME: consider replacing this policy test
-                      ;; with some tests for the STARTx and ENDx
-                      ;; indices being valid, conditional on high
-                      ;; SAFETY code.
-                      ;;
-                      ;; FIXME: It turns out that this transform is
-                      ;; critical for the performance of string
-                      ;; streams.  Make this more explicit.
-                      :policy (< (max safety space) 3))
-  `(locally
-     (declare (optimize (safety 0)))
-     (bit-bash-copy string2
-                   (the index
-                        (+ (the index (* start2 sb!vm:n-byte-bits))
-                           ,vector-data-bit-offset))
-                   string1
-                   (the index
-                        (+ (the index (* start1 sb!vm:n-byte-bits))
-                           ,vector-data-bit-offset))
-                   (the index
-                        (* (min (the index (- (or end1 (length string1))
-                                              start1))
-                                (the index (- (or end2 (length string2))
-                                              start2)))
-                           sb!vm:n-byte-bits)))
-     string1))
-
-;;; FIXME: It seems as though it should be possible to make a DEFUN
-;;; %CONCATENATE (with a DEFTRANSFORM to translate constant RTYPE to
-;;; CTYPE before calling %CONCATENATE) which is comparably efficient,
-;;; at least once DYNAMIC-EXTENT works.
+;;; FIXME: In the copy loops below, we code the loops in a strange
+;;; fashion:
+;;;
+;;; (do ((i (+ src-offset length) (1- i)))
+;;;     ((<= i 0) ...)
+;;;   (... (aref foo (1- i)) ...))
+;;;
+;;; rather than the more natural (and seemingly more efficient):
+;;;
+;;; (do ((i (1- (+ src-offset length)) (1- i)))
+;;;     ((< i 0) ...)
+;;;   (... (aref foo i) ...))
+;;;
+;;; (more efficient because we don't have to do the index adjusting on
+;;; every iteration of the loop)
+;;;
+;;; We do this to avoid a suboptimality in SBCL's backend.  In the
+;;; latter case, the backend thinks I is a FIXNUM (which it is), but
+;;; when used as an array index, the backend thinks I is a
+;;; POSITIVE-FIXNUM (which it is).  However, since the backend thinks of
+;;; these as distinct storage classes, it cannot coerce a move from a
+;;; FIXNUM TN to a POSITIVE-FIXNUM TN.  The practical effect of this
+;;; deficiency is that we have two extra moves and increased register
+;;; pressure, which can lead to some spectacularly bad register
+;;; allocation.  (sub-FIXME: the register allocation even with the
+;;; strangely written loops is not always excellent, either...).  Doing
+;;; it the first way, above, means that I is always thought of as a
+;;; POSITIVE-FIXNUM and there are no issues.
+;;;
+;;; Besides, the *-WITH-OFFSET machinery will fold those index
+;;; adjustments in the first version into the array addressing at no
+;;; performance penalty!
+
+;;; This transform is critical to the performance of string streams.  If
+;;; you tweak it, make sure that you compare the disassembly, if not the
+;;; performance of, the functions implementing string streams
+;;; (e.g. SB!IMPL::STRING-OUCH).
+(eval-when (#-sb-xc :compile-toplevel :load-toplevel :execute)
+  (defun make-replace-transform (saetp sequence-type1 sequence-type2)
+    `(deftransform replace ((seq1 seq2 &key (start1 0) (start2 0) end1 end2)
+                            (,sequence-type1 ,sequence-type2 &rest t)
+                            ,sequence-type1
+                            :node node)
+       `(let* ((len1 (length seq1))
+               (len2 (length seq2))
+               (end1 (or end1 len1))
+               (end2 (or end2 len2))
+               (replace-len (min (- end1 start1) (- end2 start2))))
+          ,(unless (policy node (= insert-array-bounds-checks 0))
+             `(progn
+                (unless (<= 0 start1 end1 len1)
+                  (sequence-bounding-indices-bad-error seq1 start1 end1))
+                (unless (<= 0 start2 end2 len2)
+                  (sequence-bounding-indices-bad-error seq2 start2 end2))))
+          ,',(cond
+               ((and saetp (sb!vm:valid-bit-bash-saetp-p saetp))
+                (let* ((n-element-bits (sb!vm:saetp-n-bits saetp))
+                       (bash-function (intern (format nil "UB~D-BASH-COPY"
+                                                      n-element-bits)
+                                              (find-package "SB!KERNEL"))))
+                  `(funcall (function ,bash-function) seq2 start2
+                    seq1 start1 replace-len)))
+               (t
+                `(if (and
+                      ;; If the sequence types are different, SEQ1 and
+                      ;; SEQ2 must be distinct arrays.
+                      ,(eql sequence-type1 sequence-type2)
+                      (eq seq1 seq2) (> start1 start2))
+                     (do ((i (truly-the index (+ start1 replace-len -1))
+                             (1- i))
+                          (j (truly-the index (+ start2 replace-len -1))
+                             (1- j)))
+                         ((< i start1))
+                       (declare (optimize (insert-array-bounds-checks 0)))
+                       (setf (aref seq1 i) (aref seq2 j)))
+                     (do ((i start1 (1+ i))
+                          (j start2 (1+ j))
+                          (end (+ start1 replace-len)))
+                         ((>= i end))
+                       (declare (optimize (insert-array-bounds-checks 0)))
+                       (setf (aref seq1 i) (aref seq2 j))))))
+          seq1))))
+
+(macrolet
+    ((define-replace-transforms ()
+       (loop for saetp across sb!vm:*specialized-array-element-type-properties*
+             for sequence-type = `(simple-array ,(sb!vm:saetp-specifier saetp) (*))
+             unless (= (sb!vm:saetp-typecode saetp) sb!vm::simple-array-nil-widetag)
+             collect (make-replace-transform saetp sequence-type sequence-type)
+             into forms
+             finally (return `(progn ,@forms))))
+     (define-one-transform (sequence-type1 sequence-type2)
+       (make-replace-transform nil sequence-type1 sequence-type2)))
+  (define-replace-transforms)
+  #!+sb-unicode
+  (progn
+   (define-one-transform (simple-array base-char (*)) (simple-array character (*)))
+   (define-one-transform (simple-array character (*)) (simple-array base-char (*)))))
+
+;;; Expand simple cases of UB<SIZE>-BASH-COPY inline.  "simple" is
+;;; defined as those cases where we are doing word-aligned copies from
+;;; both the source and the destination and we are copying from the same
+;;; offset from both the source and the destination.  (The last
+;;; condition is there so we can determine the direction to copy at
+;;; compile time rather than runtime.  Remember that UB<SIZE>-BASH-COPY
+;;; acts like memmove, not memcpy.)  These conditions may seem rather
+;;; restrictive, but they do catch common cases, like allocating a (* 2
+;;; N)-size buffer and blitting in the old N-size buffer in.
+
+(defun frob-bash-transform (src src-offset
+                            dst dst-offset
+                            length n-elems-per-word)
+  (declare (ignore src dst length))
+  (let ((n-bits-per-elem (truncate sb!vm:n-word-bits n-elems-per-word)))
+    (multiple-value-bind (src-word src-elt)
+        (truncate (lvar-value src-offset) n-elems-per-word)
+      (multiple-value-bind (dst-word dst-elt)
+          (truncate (lvar-value dst-offset) n-elems-per-word)
+        ;; Avoid non-word aligned copies.
+        (unless (and (zerop src-elt) (zerop dst-elt))
+          (give-up-ir1-transform))
+        ;; Avoid copies where we would have to insert code for
+        ;; determining the direction of copying.
+        (unless (= src-word dst-word)
+          (give-up-ir1-transform))
+        ;; FIXME: The cross-compiler doesn't optimize TRUNCATE properly,
+        ;; so we have to do its work here.
+        `(let ((end (+ ,src-word ,(if (= n-elems-per-word 1)
+                                      'length
+                                      `(truncate (the index length) ,n-elems-per-word)))))
+           (declare (type index end))
+           ;; Handle any bits at the end.
+           (when (logtest length (1- ,n-elems-per-word))
+             (let* ((extra (mod length ,n-elems-per-word))
+                    ;; FIXME: The shift amount on this ASH is
+                    ;; *always* negative, but the backend doesn't
+                    ;; have a NEGATIVE-FIXNUM primitive type, so we
+                    ;; wind up with a pile of code that tests the
+                    ;; sign of the shift count prior to shifting when
+                    ;; all we need is a simple negate and shift
+                    ;; right.  Yuck.
+                    (mask (ash #.(1- (ash 1 sb!vm:n-word-bits))
+                               (* (- extra ,n-elems-per-word)
+                                  ,n-bits-per-elem))))
+               (setf (sb!kernel:%vector-raw-bits dst end)
+                     (logior
+                      (logandc2 (sb!kernel:%vector-raw-bits dst end)
+                                (ash mask
+                                     ,(ecase sb!c:*backend-byte-order*
+                                             (:little-endian 0)
+                                             (:big-endian `(* (- ,n-elems-per-word extra)
+                                                              ,n-bits-per-elem)))))
+                      (logand (sb!kernel:%vector-raw-bits src end)
+                              (ash mask
+                                   ,(ecase sb!c:*backend-byte-order*
+                                           (:little-endian 0)
+                                           (:big-endian `(* (- ,n-elems-per-word extra)
+                                                            ,n-bits-per-elem)))))))))
+           ;; Copy from the end to save a register.
+           (do ((i end (1- i)))
+               ((<= i ,src-word))
+             (setf (sb!kernel:%vector-raw-bits dst (1- i))
+                   (sb!kernel:%vector-raw-bits src (1- i))))
+           (values))))))
+
+#.(loop for i = 1 then (* i 2)
+        collect `(deftransform ,(intern (format nil "UB~D-BASH-COPY" i)
+                                        "SB!KERNEL")
+                                                        ((src src-offset
+                                                          dst dst-offset
+                                                          length)
+                                                        ((simple-unboxed-array (*))
+                                                         (constant-arg index)
+                                                         (simple-unboxed-array (*))
+                                                         (constant-arg index)
+                                                         index)
+                                                        *)
+                  (frob-bash-transform src src-offset
+                                       dst dst-offset length
+                                       ,(truncate sb!vm:n-word-bits i))) into forms
+        until (= i sb!vm:n-word-bits)
+        finally (return `(progn ,@forms)))
+
+;;; We expand copy loops inline in SUBSEQ and COPY-SEQ if we're copying
+;;; arrays with elements of size >= the word size.  We do this because
+;;; we know the arrays cannot alias (one was just consed), therefore we
+;;; can determine at compile time the direction to copy, and for
+;;; word-sized elements, UB<WORD-SIZE>-BASH-COPY will do a bit of
+;;; needless checking to figure out what's going on.  The same
+;;; considerations apply if we are copying elements larger than the word
+;;; size, with the additional twist that doing it inline is likely to
+;;; cons far less than calling REPLACE and letting generic code do the
+;;; work.
+;;;
+;;; However, we do not do this for elements whose size is < than the
+;;; word size because we don't want to deal with any alignment issues
+;;; inline.  The UB*-BASH-COPY transforms might fix things up later
+;;; anyway.
+
+(defun maybe-expand-copy-loop-inline (src src-offset dst dst-offset length
+                                      element-type)
+  (let ((saetp (find-saetp element-type)))
+    (aver saetp)
+    (if (>= (sb!vm:saetp-n-bits saetp) sb!vm:n-word-bits)
+        (expand-aref-copy-loop src src-offset dst dst-offset length)
+        `(locally (declare (optimize (safety 0)))
+           (replace ,dst ,src :start1 ,dst-offset :start2 ,src-offset :end1 ,length)))))
+
+(defun expand-aref-copy-loop (src src-offset dst dst-offset length)
+  (if (eql src-offset dst-offset)
+      `(do ((i (+ ,src-offset ,length) (1- i)))
+           ((<= i ,src-offset))
+         (declare (optimize (insert-array-bounds-checks 0)))
+         (setf (aref ,dst (1- i)) (aref ,src (1- i))))
+      ;; KLUDGE: The compiler is not able to derive that (+ offset
+      ;; length) must be a fixnum, but arrives at (unsigned-byte 29).
+      ;; We, however, know it must be so, as by this point the bounds
+      ;; have already been checked.
+      `(do ((i (truly-the fixnum (+ ,src-offset ,length)) (1- i))
+            (j (+ ,dst-offset ,length) (1- j)))
+           ((<= i ,src-offset))
+         (declare (optimize (insert-array-bounds-checks 0))
+                  (type (integer 0 #.sb!xc:array-dimension-limit) j i))
+         (setf (aref ,dst (1- j)) (aref ,src (1- i))))))
+
+;;; SUBSEQ, COPY-SEQ
+
+(deftransform subseq ((seq start &optional end)
+                      (vector t &optional t)
+                      *
+                      :node node)
+  (let ((type (lvar-type seq)))
+    (cond
+      ((and (array-type-p type)
+            (csubtypep type (specifier-type '(or (simple-unboxed-array (*)) simple-vector)))
+            (policy node (> speed space)))
+       (let ((element-type (type-specifier (array-type-specialized-element-type type))))
+         `(let* ((length (length seq))
+                 (end (or end length)))
+            ,(unless (policy node (zerop insert-array-bounds-checks))
+                     '(progn
+                       (unless (<= 0 start end length)
+                         (sequence-bounding-indices-bad-error seq start end))))
+            (let* ((size (- end start))
+                   (result (make-array size :element-type ',element-type)))
+              ,(maybe-expand-copy-loop-inline 'seq (if (constant-lvar-p start)
+                                                       (lvar-value start)
+                                                       'start)
+                                              'result 0 'size element-type)
+              result))))
+      (t
+       '(vector-subseq* seq start end)))))
+
+(deftransform subseq ((seq start &optional end)
+                      (list t &optional t))
+  `(list-subseq* seq start end))
+
+(deftransform subseq ((seq start &optional end)
+                      ((and sequence (not vector) (not list)) t &optional t))
+  '(sb!sequence:subseq seq start end))
+
+(deftransform copy-seq ((seq) (vector))
+  (let ((type (lvar-type seq)))
+    (cond ((and (array-type-p type)
+                (csubtypep type (specifier-type '(or (simple-unboxed-array (*)) simple-vector))))
+           (let ((element-type (type-specifier (array-type-specialized-element-type type))))
+             `(let* ((length (length seq))
+                     (result (make-array length :element-type ',element-type)))
+                ,(maybe-expand-copy-loop-inline 'seq 0 'result 0 'length element-type)
+                result)))
+          (t
+           '(vector-subseq* seq 0 nil)))))
+
+(deftransform copy-seq ((seq) (list))
+  '(list-copy-seq* seq))
+
+(deftransform copy-seq ((seq) ((and sequence (not vector) (not list))))
+  '(sb!sequence:copy-seq seq))
+
+;;; FIXME: it really should be possible to take advantage of the
+;;; macros used in code/seq.lisp here to avoid duplication of code,
+;;; and enable even funkier transformations.
+(deftransform search ((pattern text &key (start1 0) (start2 0) end1 end2
+                               (test #'eql)
+                               (key #'identity)
+                               from-end)
+                      (vector vector &rest t)
+                      *
+                      :node node
+                      :policy (> speed (max space safety)))
+  "open code"
+  (flet ((maybe (x)
+           (when (lvar-p x)
+             (if (constant-lvar-p x)
+                 (when (lvar-value x)
+                   :yes)
+                 :maybe))))
+    (let ((from-end (when (lvar-p from-end)
+                     (unless (constant-lvar-p from-end)
+                       (give-up-ir1-transform ":FROM-END is not constant."))
+                     (lvar-value from-end)))
+         (key? (maybe key))
+         (test? (maybe test))
+         (check-bounds-p (policy node (plusp insert-array-bounds-checks))))
+     `(block search
+        (flet ((oops (vector start end)
+                 (sequence-bounding-indices-bad-error vector start end)))
+          (let* ((len1 (length pattern))
+                 (len2 (length text))
+                 (end1 (or end1 len1))
+                 (end2 (or end2 len2))
+                 ,@(case key?
+                     (:yes `((key (%coerce-callable-to-fun key))))
+                     (:maybe `((key (when key
+                                      (%coerce-callable-to-fun key))))))
+                 ,@(when test?
+                     `((test (%coerce-callable-to-fun test)))))
+            (declare (type index start1 start2 end1 end2))
+            ,@(when check-bounds-p
+                `((unless (<= start1 end1 len1)
+                    (oops pattern start1 end1))
+                  (unless (<= start2 end2 len2)
+                    (oops pattern start2 end2))))
+            (when (= end1 start1)
+              (return-from search (if from-end
+                                      end2
+                                      start2)))
+            (do (,(if from-end
+                      '(index2 (- end2 (- end1 start1)) (1- index2))
+                      '(index2 start2 (1+ index2))))
+                (,(if from-end
+                      '(< index2 start2)
+                      '(>= index2 end2))
+                 nil)
+              ;; INDEX2 is FIXNUM, not an INDEX, as right before the loop
+              ;; terminates is hits -1 when :FROM-END is true and :START2
+              ;; is 0.
+              (declare (type fixnum index2))
+              (when (do ((index1 start1 (1+ index1))
+                         (index2 index2 (1+ index2)))
+                        ((>= index1 end1) t)
+                      (declare (type index index1 index2)
+                               (optimize (insert-array-bounds-checks 0)))
+                      ,@(unless from-end
+                          '((when (= index2 end2)
+                              (return-from search nil))))
+                      (unless (,@(if test?
+                                     `(funcall test)
+                                     `(eql))
+                               ,(case key?
+                                  (:yes `(funcall key (aref pattern index1)))
+                                  (:maybe `(let ((elt (aref pattern index1)))
+                                             (if key
+                                                 (funcall key elt)
+                                                 elt)))
+                                  (otherwise `(aref pattern index1)))
+                               ,(case key?
+                                  (:yes `(funcall key (aref text index2)))
+                                  (:maybe `(let ((elt (aref text index2)))
+                                             (if key
+                                                 (funcall key elt)
+                                                 elt)))
+                                  (otherwise `(aref text index2))))
+                        (return nil)))
+                (return index2)))))))))
+
+
+;;; Open-code CONCATENATE for strings. It would be possible to extend
+;;; this transform to non-strings, but I chose to just do the case that
+;;; should cover 95% of CONCATENATE performance complaints for now.
+;;;   -- JES, 2007-11-17
 ;;;
-;;; FIXME: currently KLUDGEed because of bug 188
-(deftransform concatenate ((rtype &rest sequences)
-                          (t &rest (or simple-base-string
-                                       (simple-array nil (*))))
-                          simple-base-string
-                          :policy (< safety 3))
-  (loop for rest-seqs on sequences
-        for n-seq = (gensym "N-SEQ")
-        for n-length = (gensym "N-LENGTH")
-        for start = vector-data-bit-offset then next-start
-        for next-start = (gensym "NEXT-START")
-        collect n-seq into args
-        collect `(,n-length (* (length ,n-seq) sb!vm:n-byte-bits)) into lets
-        collect n-length into all-lengths
-        collect next-start into starts
-        collect `(if (and (typep ,n-seq '(simple-array nil (*)))
-                         (> ,n-length 0))
-                    (error 'nil-array-accessed-error)
-                    (bit-bash-copy ,n-seq ,vector-data-bit-offset
-                                   res ,start ,n-length))
-                into forms
-        collect `(setq ,next-start (+ ,start ,n-length)) into forms
-        finally
-        (return
-          `(lambda (rtype ,@args)
-             (declare (ignore rtype))
-             (let* (,@lets
-                      (res (make-string (truncate (the index (+ ,@all-lengths))
-                                                  sb!vm:n-byte-bits))))
-               (declare (type index ,@all-lengths))
-               (let (,@(mapcar (lambda (name) `(,name 0)) starts))
-                 (declare (type index ,@starts))
-                 ,@forms)
-               res)))))
+;;; Only handle the simple result type cases. If somebody does (CONCATENATE
+;;; '(STRING 6) ...) their code won't be optimized, but nobody does that in
+;;; practice.
+;;;
+;;; Limit full open coding based on length of constant sequences. Default
+;;; value is chosen so that other parts of the compiler (constraint propagation
+;;; mainly) won't go nonlinear too badly. It's not an exact number -- but
+;;; in the right ballpark.
+(defvar *concatenate-open-code-limit* 129)
+
+(deftransform concatenate ((result-type &rest lvars)
+                           ((constant-arg
+                             (member string simple-string base-string simple-base-string))
+                            &rest sequence)
+                           * :node node)
+  (let ((vars (loop for x in lvars collect (gensym)))
+        (type (lvar-value result-type)))
+    (if (policy node (<= speed space))
+        ;; Out-of-line
+        `(lambda (.dummy. ,@vars)
+           (declare (ignore .dummy.))
+           ,(ecase type
+              ((string simple-string)
+               `(%concatenate-to-string ,@vars))
+              ((base-string simple-base-string)
+               `(%concatenate-to-base-string ,@vars))))
+        ;; Inline
+        (let* ((element-type (ecase type
+                               ((string simple-string) 'character)
+                               ((base-string simple-base-string) 'base-char)))
+               (lvar-values (loop for lvar in lvars
+                                  collect (when (constant-lvar-p lvar)
+                                            (lvar-value lvar))))
+               (lengths
+                 (loop for value in lvar-values
+                       for var in vars
+                       collect (if value
+                                   (length value)
+                                   `(sb!impl::string-dispatch ((simple-array * (*))
+                                                               sequence)
+                                                              ,var
+                                      (declare (muffle-conditions compiler-note))
+                                      (length ,var)))))
+               (non-constant-start
+                 (loop for value in lvar-values
+                       while (and (stringp value)
+                                    (< (length value) *concatenate-open-code-limit*))
+                       sum (length value))))
+          `(apply
+            (lambda ,vars
+              (declare (ignorable ,@vars))
+              (declare (optimize (insert-array-bounds-checks 0)))
+              (let* ((.length. (+ ,@lengths))
+                     (.pos. ,non-constant-start)
+                     (.string. (make-string .length. :element-type ',element-type)))
+                (declare (type index .length. .pos.)
+                         (muffle-conditions compiler-note))
+                ,@(loop with first-constants = t
+                        for first = t then nil
+                        for value in lvar-values
+                        for var in vars
+                        collect
+                        (cond ((and (stringp value)
+                                    (< (length value) *concatenate-open-code-limit*))
+                               ;; Fold the array reads for constant arguments
+                               `(progn
+                                  ,@(loop for c across value
+                                          for i from 0
+                                          collect
+                                          ;; Without truly-the we get massive numbers
+                                          ;; of pointless error traps.
+                                          `(setf (aref .string.
+                                                       (truly-the index ,(if first-constants
+                                                                             i
+                                                                             `(+ .pos. ,i))))
+                                                 ,c))
+                                  ,(unless first-constants
+                                     `(incf (truly-the index .pos.) ,(length value)))))
+                              (t
+                               (prog1
+                                   `(sb!impl::string-dispatch
+                                        (#!+sb-unicode
+                                         (simple-array character (*))
+                                         (simple-array base-char (*))
+                                         t)
+                                        ,var
+                                      (replace .string. ,var
+                                               ,@(cond ((not first-constants)
+                                                        '(:start1 .pos.))
+                                                       ((plusp non-constant-start)
+                                                        `(:start1 ,non-constant-start))))
+                                      (incf (truly-the index .pos.) (length ,var)))
+                                 (setf first-constants nil)))))
+                .string.))
+            lvars)))))
 \f
 ;;;; CONS accessor DERIVE-TYPE optimizers
 
 (defoptimizer (car derive-type) ((cons))
-  (let ((type (continuation-type cons))
-       (null-type (specifier-type 'null)))
+  ;; This and CDR needs to use LVAR-CONSERVATIVE-TYPE because type inference
+  ;; gets confused by things like (SETF CAR).
+  (let ((type (lvar-conservative-type cons))
+        (null-type (specifier-type 'null)))
     (cond ((eq type null-type)
-          null-type)
-         ((cons-type-p type)
-          (cons-type-car-type type)))))
+           null-type)
+          ((cons-type-p type)
+           (cons-type-car-type type)))))
 
 (defoptimizer (cdr derive-type) ((cons))
-  (let ((type (continuation-type cons))
-       (null-type (specifier-type 'null)))
+  (let ((type (lvar-conservative-type cons))
+        (null-type (specifier-type 'null)))
     (cond ((eq type null-type)
-          null-type)
-         ((cons-type-p type)
-          (cons-type-cdr-type type)))))
+           null-type)
+          ((cons-type-p type)
+           (cons-type-cdr-type type)))))
 \f
 ;;;; FIND, POSITION, and their -IF and -IF-NOT variants
 
 ;;; %FIND-POSITION-IF only when %FIND-POSITION-IF has an inline
 ;;; expansion, so we factor out the condition into this function.
 (defun check-inlineability-of-find-position-if (sequence from-end)
-  (let ((ctype (continuation-type sequence)))
+  (let ((ctype (lvar-type sequence)))
     (cond ((csubtypep ctype (specifier-type 'vector))
-          ;; It's not worth trying to inline vector code unless we
-          ;; know a fair amount about it at compile time.
-          (upgraded-element-type-specifier-or-give-up sequence)
-          (unless (constant-continuation-p from-end)
-            (give-up-ir1-transform
-             "FROM-END argument value not known at compile time")))
-         ((csubtypep ctype (specifier-type 'list))
-          ;; Inlining on lists is generally worthwhile.
-          ) 
-         (t
-          (give-up-ir1-transform
-           "sequence type not known at compile time")))))
+           ;; It's not worth trying to inline vector code unless we
+           ;; know a fair amount about it at compile time.
+           (upgraded-element-type-specifier-or-give-up sequence)
+           (unless (constant-lvar-p from-end)
+             (give-up-ir1-transform
+              "FROM-END argument value not known at compile time")))
+          ((csubtypep ctype (specifier-type 'list))
+           ;; Inlining on lists is generally worthwhile.
+           )
+          (t
+           (give-up-ir1-transform
+            "sequence type not known at compile time")))))
 
 ;;; %FIND-POSITION-IF and %FIND-POSITION-IF-NOT for LIST data
 (macrolet ((def (name condition)
-            `(deftransform ,name ((predicate sequence from-end start end key)
-                                  (function list t t t function)
-                                  *
-                                  :policy (> speed space)
-                                  :important t)
-               "expand inline"
-               `(let ((index 0)
-                      (find nil)
-                      (position nil))
-                  (declare (type index index))
-                  (dolist (i sequence
-                           (if (and end (> end index))
-                               (sb!impl::signal-bounding-indices-bad-error
-                                sequence start end)
-                               (values find position)))
-                    (let ((key-i (funcall key i)))
-                      (when (and end (>= index end))
-                        (return (values find position)))
-                      (when (>= index start)
-                        (,',condition (funcall predicate key-i)
-                         ;; This hack of dealing with non-NIL
-                         ;; FROM-END for list data by iterating
-                         ;; forward through the list and keeping
-                         ;; track of the last time we found a match
-                         ;; might be more screwy than what the user
-                         ;; expects, but it seems to be allowed by
-                         ;; the ANSI standard. (And if the user is
-                         ;; screwy enough to ask for FROM-END
-                         ;; behavior on list data, turnabout is
-                         ;; fair play.)
-                         ;;
-                         ;; It's also not enormously efficient,
-                         ;; calling PREDICATE and KEY more often
-                         ;; than necessary; but all the
-                         ;; alternatives seem to have their own
-                         ;; efficiency problems.
-                         (if from-end
-                             (setf find i
-                                   position index)
-                             (return (values i index))))))
-                    (incf index))))))
+             `(deftransform ,name ((predicate sequence from-end start end key)
+                                   (function list t t t function)
+                                   *
+                                   :policy (> speed space))
+                "expand inline"
+                `(let ((find nil)
+                       (position nil))
+                   (flet ((bounds-error ()
+                            (sequence-bounding-indices-bad-error sequence start end)))
+                     (if (and end (> start end))
+                         (bounds-error)
+                         (do ((slow sequence (cdr slow))
+                              (fast (cdr sequence) (cddr fast))
+                              (index 0 (+ index 1)))
+                             ((cond ((null slow)
+                                     (if (and end (> end index))
+                                         (bounds-error)
+                                         (return (values find position))))
+                                    ((and end (>= index end))
+                                     (return (values find position)))
+                                    ((eq slow fast)
+                                     (circular-list-error sequence)))
+                              (bug "never"))
+                           (declare (list slow fast))
+                           (when (>= index start)
+                             (let* ((element (car slow))
+                                    (key-i (funcall key element)))
+                               (,',condition (funcall predicate key-i)
+                                             ;; This hack of dealing with non-NIL
+                                             ;; FROM-END for list data by iterating
+                                             ;; forward through the list and keeping
+                                             ;; track of the last time we found a
+                                             ;; match might be more screwy than what
+                                             ;; the user expects, but it seems to be
+                                             ;; allowed by the ANSI standard. (And
+                                             ;; if the user is screwy enough to ask
+                                             ;; for FROM-END behavior on list data,
+                                             ;; turnabout is fair play.)
+                                             ;;
+                                             ;; It's also not enormously efficient,
+                                             ;; calling PREDICATE and KEY more often
+                                             ;; than necessary; but all the
+                                             ;; alternatives seem to have their own
+                                             ;; efficiency problems.
+                                             (if from-end
+                                                 (setf find element
+                                                       position index)
+                                                 (return (values element index)))))))))))))
   (def %find-position-if when)
   (def %find-position-if-not unless))
-                     
+
 ;;; %FIND-POSITION for LIST data can be expanded into %FIND-POSITION-IF
 ;;; without loss of efficiency. (I.e., the optimizer should be able
 ;;; to straighten everything out.)
 (deftransform %find-position ((item sequence from-end start end key test)
-                             (t list t t t t t)
-                             *
-                             :policy (> speed space)
-                             :important t)
+                              (t list t t t t t)
+                              *
+                              :policy (> speed space))
   "expand inline"
   '(%find-position-if (let ((test-fun (%coerce-callable-to-fun test)))
-                       ;; The order of arguments for asymmetric tests
-                       ;; (e.g. #'<, as opposed to order-independent
-                       ;; tests like #'=) is specified in the spec
-                       ;; section 17.2.1 -- the O/Zi stuff there.
-                       (lambda (i)
-                         (funcall test-fun item i)))
-                     sequence
-                     from-end
-                     start
-                     end
-                     (%coerce-callable-to-fun key)))
+                        ;; The order of arguments for asymmetric tests
+                        ;; (e.g. #'<, as opposed to order-independent
+                        ;; tests like #'=) is specified in the spec
+                        ;; section 17.2.1 -- the O/Zi stuff there.
+                        (lambda (i)
+                          (funcall test-fun item i)))
+                      sequence
+                      from-end
+                      start
+                      end
+                      (%coerce-callable-to-fun key)))
 
 ;;; The inline expansions for the VECTOR case are saved as macros so
 ;;; that we can share them between the DEFTRANSFORMs and the default
 ;;; cases in the DEFUNs. (This isn't needed for the LIST case, because
 ;;; the DEFTRANSFORMs for LIST are less choosy about when to expand.)
 (defun %find-position-or-find-position-if-vector-expansion (sequence-arg
-                                                           from-end
-                                                           start
-                                                           end-arg
-                                                           element
-                                                           done-p-expr)
-  (with-unique-names (offset block index n-sequence sequence n-end end)
-    `(let ((,n-sequence ,sequence-arg)
-          (,n-end ,end-arg))
+                                                            from-end
+                                                            start
+                                                            end-arg
+                                                            element
+                                                            done-p-expr)
+  (with-unique-names (offset block index n-sequence sequence end)
+    `(let* ((,n-sequence ,sequence-arg))
        (with-array-data ((,sequence ,n-sequence :offset-var ,offset)
-                        (,start ,start)
-                        (,end (%check-vector-sequence-bounds
-                               ,n-sequence ,start ,n-end)))
+                         (,start ,start)
+                         (,end ,end-arg)
+                         :check-fill-pointer t)
          (block ,block
-          (macrolet ((maybe-return ()
-                       '(let ((,element (aref ,sequence ,index)))
-                          (when ,done-p-expr
-                            (return-from ,block
-                              (values ,element
-                                      (- ,index ,offset)))))))
-            (if ,from-end
-                (loop for ,index
-                      ;; (If we aren't fastidious about declaring that 
-                      ;; INDEX might be -1, then (FIND 1 #() :FROM-END T)
-                      ;; can send us off into never-never land, since
-                      ;; INDEX is initialized to -1.)
-                      of-type index-or-minus-1
-                      from (1- ,end) downto ,start do
-                      (maybe-return))
-                (loop for ,index of-type index from ,start below ,end do
-                      (maybe-return))))
-          (values nil nil))))))
+           (macrolet ((maybe-return ()
+                        ;; WITH-ARRAY-DATA has already performed bounds
+                        ;; checking, so we can safely elide the checks
+                        ;; in the inner loop.
+                        '(let ((,element (locally (declare (optimize (insert-array-bounds-checks 0)))
+                                           (aref ,sequence ,index))))
+                          (when ,done-p-expr
+                            (return-from ,block
+                              (values ,element
+                                      (- ,index ,offset)))))))
+             (if ,from-end
+                 (loop for ,index
+                       ;; (If we aren't fastidious about declaring that
+                       ;; INDEX might be -1, then (FIND 1 #() :FROM-END T)
+                       ;; can send us off into never-never land, since
+                       ;; INDEX is initialized to -1.)
+                       of-type index-or-minus-1
+                       from (1- ,end) downto ,start do
+                       (maybe-return))
+                 (loop for ,index of-type index from ,start below ,end do
+                          (maybe-return))))
+           (values nil nil))))))
 
 (def!macro %find-position-vector-macro (item sequence
-                                            from-end start end key test)
+                                             from-end start end key test)
   (with-unique-names (element)
     (%find-position-or-find-position-if-vector-expansion
      sequence
      `(funcall ,test ,item (funcall ,key ,element)))))
 
 (def!macro %find-position-if-vector-macro (predicate sequence
-                                                    from-end start end key)
+                                                     from-end start end key)
   (with-unique-names (element)
     (%find-position-or-find-position-if-vector-expansion
      sequence
      `(funcall ,predicate (funcall ,key ,element)))))
 
 (def!macro %find-position-if-not-vector-macro (predicate sequence
-                                                        from-end start end key)
+                                                         from-end start end key)
   (with-unique-names (element)
     (%find-position-or-find-position-if-vector-expansion
      sequence
 ;;; %FIND-POSITION, %FIND-POSITION-IF and %FIND-POSITION-IF-NOT for
 ;;; VECTOR data
 (deftransform %find-position-if ((predicate sequence from-end start end key)
-                                (function vector t t t function)
-                                *
-                                :policy (> speed space)
-                                :important t)
+                                 (function vector t t t function)
+                                 *
+                                 :policy (> speed space))
   "expand inline"
   (check-inlineability-of-find-position-if sequence from-end)
   '(%find-position-if-vector-macro predicate sequence
-                                  from-end start end key))
+                                   from-end start end key))
 
 (deftransform %find-position-if-not ((predicate sequence from-end start end key)
-                                    (function vector t t t function)
-                                    *
-                                    :policy (> speed space)
-                                    :important t)
+                                     (function vector t t t function)
+                                     *
+                                     :policy (> speed space))
   "expand inline"
   (check-inlineability-of-find-position-if sequence from-end)
   '(%find-position-if-not-vector-macro predicate sequence
                                        from-end start end key))
 
 (deftransform %find-position ((item sequence from-end start end key test)
-                             (t vector t t t function function)
-                             *
-                             :policy (> speed space)
-                             :important t)
+                              (t vector t t t function function)
+                              *
+                              :policy (> speed space))
   "expand inline"
   (check-inlineability-of-find-position-if sequence from-end)
   '(%find-position-vector-macro item sequence
-                               from-end start end key test))
+    from-end start end key test))
+
+(deftransform %find-position ((item sequence from-end start end key test)
+                              (t bit-vector t t t t t)
+                              * :node node)
+  (when (and test (lvar-fun-is test '(eq eql equal)))
+    (setf test nil))
+  (when (and key (lvar-fun-is key '(identity)))
+    (setf key nil))
+  (when (or test key)
+    (delay-ir1-transform node :optimize)
+    (give-up-ir1-transform "non-trivial :KEY or :TEST"))
+  (catch 'not-a-bit
+    `(with-array-data ((bits sequence :offset-var offset)
+                       (start start)
+                       (end end)
+                       :check-fill-pointer t)
+       (let ((p ,(if (constant-lvar-p item)
+                     (case (lvar-value item)
+                       (0 `(%bit-position/0 bits from-end start end))
+                       (1 `(%bit-position/1 bits from-end start end))
+                       (otherwise (throw 'not-a-bit `(values nil nil))))
+                     `(%bit-position item bits from-end start end))))
+         (if p
+             (values item (the index (- (truly-the index p) offset)))
+             (values nil nil))))))
+
+(deftransform %find-position ((item sequence from-end start end key test)
+                              (character string t t t function function)
+                              *
+                              :policy (> speed space))
+  (if (eq '* (upgraded-element-type-specifier sequence))
+      (let ((form
+             `(sb!impl::string-dispatch ((simple-array character (*))
+                                         (simple-array base-char (*))
+                                         (simple-array nil (*)))
+                  sequence
+                (%find-position item sequence from-end start end key test))))
+        (if (csubtypep (lvar-type sequence) (specifier-type 'simple-string))
+            form
+            ;; Otherwise we'd get three instances of WITH-ARRAY-DATA from
+            ;; %FIND-POSITION.
+            `(with-array-data ((sequence sequence :offset-var offset)
+                               (start start)
+                               (end end)
+                               :check-fill-pointer t)
+               (multiple-value-bind (elt index) ,form
+                 (values elt (when (fixnump index) (- index offset)))))))
+      ;; The type is known exactly, other transforms will take care of it.
+      (give-up-ir1-transform)))
 
 ;;; logic to unravel :TEST, :TEST-NOT, and :KEY options in FIND,
 ;;; POSITION-IF, etc.
 (define-source-transform effective-find-position-test (test test-not)
   (once-only ((test test)
-             (test-not test-not))
+              (test-not test-not))
     `(cond
       ((and ,test ,test-not)
        (error "can't specify both :TEST and :TEST-NOT"))
 (define-source-transform effective-find-position-key (key)
   (once-only ((key key))
     `(if ,key
-        (%coerce-callable-to-fun ,key)
-        #'identity)))
+         (%coerce-callable-to-fun ,key)
+         #'identity)))
 
 (macrolet ((define-find-position (fun-name values-index)
-            `(deftransform ,fun-name ((item sequence &key
-                                            from-end (start 0) end
-                                            key test test-not))
-               '(nth-value ,values-index
-                           (%find-position item sequence
-                                           from-end start
-                                           end
-                                           (effective-find-position-key key)
-                                           (effective-find-position-test
-                                            test test-not))))))
+             `(deftransform ,fun-name ((item sequence &key
+                                             from-end (start 0) end
+                                             key test test-not)
+                                       (t (or list vector) &rest t))
+                '(nth-value ,values-index
+                            (%find-position item sequence
+                                            from-end start
+                                            end
+                                            (effective-find-position-key key)
+                                            (effective-find-position-test
+                                             test test-not))))))
   (define-find-position find 0)
   (define-find-position position 1))
 
 (macrolet ((define-find-position-if (fun-name values-index)
-            `(deftransform ,fun-name ((predicate sequence &key
-                                                 from-end (start 0)
-                                                 end key))
-               '(nth-value
-                 ,values-index
-                 (%find-position-if (%coerce-callable-to-fun predicate)
-                                    sequence from-end
-                                    start end
-                                    (effective-find-position-key key))))))
+             `(deftransform ,fun-name ((predicate sequence &key
+                                                  from-end (start 0)
+                                                  end key)
+                                       (t (or list vector) &rest t))
+                '(nth-value
+                  ,values-index
+                  (%find-position-if (%coerce-callable-to-fun predicate)
+                                     sequence from-end
+                                     start end
+                                     (effective-find-position-key key))))))
   (define-find-position-if find-if 0)
   (define-find-position-if position-if 1))
 
 ;;;     perhaps it's worth optimizing the -if-not versions in the same
 ;;;     way as the others?
 ;;;
-;;; FIXME: Maybe remove uses of these deprecated functions (and
-;;; definitely of :TEST-NOT) within the implementation of SBCL.
+;;; FIXME: Maybe remove uses of these deprecated functions within the
+;;; implementation of SBCL.
 (macrolet ((define-find-position-if-not (fun-name values-index)
-              `(deftransform ,fun-name ((predicate sequence &key
-                                         from-end (start 0)
-                                         end key))
-                '(nth-value
-                  ,values-index
-                  (%find-position-if-not (%coerce-callable-to-fun predicate)
-                   sequence from-end
-                   start end
-                   (effective-find-position-key key))))))
+               `(deftransform ,fun-name ((predicate sequence &key
+                                          from-end (start 0)
+                                          end key)
+                                         (t (or list vector) &rest t))
+                 '(nth-value
+                   ,values-index
+                   (%find-position-if-not (%coerce-callable-to-fun predicate)
+                    sequence from-end
+                    start end
+                    (effective-find-position-key key))))))
   (define-find-position-if-not find-if-not 0)
   (define-find-position-if-not position-if-not 1))
+
+(macrolet ((define-trimmer-transform (fun-name leftp rightp)
+             `(deftransform ,fun-name ((char-bag string)
+                                       (t simple-string))
+                (let ((find-expr
+                       (if (constant-lvar-p char-bag)
+                           ;; If the bag is constant, use MEMBER
+                           ;; instead of FIND, since we have a
+                           ;; deftransform for MEMBER that can
+                           ;; open-code all of the comparisons when
+                           ;; the list is constant. -- JES, 2007-12-10
+                           `(not (member (schar string index)
+                                         ',(coerce (lvar-value char-bag) 'list)
+                                         :test #'char=))
+                           '(not (find (schar string index) char-bag :test #'char=)))))
+                  `(flet ((char-not-in-bag (index)
+                            ,find-expr))
+                     (let* ((end (length string))
+                            (left-end (if ,',leftp
+                                          (do ((index 0 (1+ index)))
+                                              ((or (= index (the fixnum end))
+                                                   (char-not-in-bag index))
+                                               index)
+                                            (declare (fixnum index)))
+                                          0))
+                            (right-end (if ,',rightp
+                                           (do ((index (1- end) (1- index)))
+                                               ((or (< index left-end)
+                                                    (char-not-in-bag index))
+                                                (1+ index))
+                                             (declare (fixnum index)))
+                                           end)))
+                       (if (and (eql left-end 0)
+                                (eql right-end (length string)))
+                           string
+                           (subseq string left-end right-end))))))))
+  (define-trimmer-transform string-left-trim t nil)
+  (define-trimmer-transform string-right-trim nil t)
+  (define-trimmer-transform string-trim t t))
+
+\f
+;;; (partially) constant-fold backq-* functions, or convert to their
+;;; plain CL equivalent (now that they're not needed for pprinting).
+
+;; Pop constant values from the end, list/list* them if any, and link
+;; the remainder with list* at runtime.
+(defun transform-backq-list-or-list* (function values)
+  (let ((gensyms (make-gensym-list (length values)))
+        (reverse (reverse values))
+        (constants '()))
+    (loop while (and reverse
+                     (constant-lvar-p (car reverse)))
+          do (push (lvar-value (pop reverse))
+                   constants))
+    (if (null constants)
+        `(lambda ,gensyms
+           (,function ,@gensyms))
+        (let ((tail (apply function constants)))
+          (if (null reverse)
+              `',tail
+              (let* ((nvariants (length reverse))
+                     (variants (subseq gensyms 0 nvariants)))
+                `(lambda ,gensyms
+                   (declare (ignore ,@(subseq gensyms nvariants)))
+                   ,(if tail
+                        `(list* ,@variants ',tail)
+                        `(list ,@variants)))))))))
+
+(deftransform sb!impl::backq-list ((&rest elts))
+  (transform-backq-list-or-list* 'list elts))
+
+(deftransform sb!impl::backq-list* ((&rest elts))
+  (transform-backq-list-or-list* 'list* elts))
+
+;; Merge adjacent constant values
+(deftransform sb!impl::backq-append ((&rest elts))
+  (let ((gensyms (make-gensym-list (length elts)))
+        (acc nil)
+        (ignored '())
+        (arguments '()))
+    (flet ((convert-accumulator ()
+             (let ((constant (apply 'append (nreverse (shiftf acc nil)))))
+               (when constant
+                 (push `',constant arguments)))))
+      (loop for gensym in gensyms
+            for (elt . next) on elts by #'cdr
+            do (cond ((constant-lvar-p elt)
+                      (let ((elt (lvar-value elt)))
+                        (when (and next (not (proper-list-p elt)))
+                          (abort-ir1-transform
+                           "Non-list or improper list spliced in ~
+                            the middle of a backquoted list."))
+                        (push gensym ignored)
+                        (push elt acc)))
+                     (t
+                      (convert-accumulator)
+                      (push gensym arguments)))
+            finally (convert-accumulator)))
+    (let ((arguments (nreverse arguments)))
+      `(lambda ,gensyms
+         (declare (ignore ,@ignored))
+         (append ,@arguments)))))
+
+;; Nothing special for nconc
+(define-source-transform sb!impl::backq-nconc (&rest elts)
+  `(nconc ,@elts))
+
+;; cons and vector are handled with regular constant folding...
+;; but we still want to convert backq-cons into cl:cons.
+(deftransform sb!impl::backq-cons ((x y))
+  `(cons x y))