X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=src%2Fcompiler%2Fsrctran.lisp;h=95dfbab9c2f9e62a0d33a9d4473efc8e3a3c760e;hb=071afc96281a1dac1938268b1cf35d7e92c7e2c0;hp=943e291163ca3ae614cc277bfde8a0295fa6a81e;hpb=5f1f553ecde8995aae8d9f9fbe1cd2b2cfb7db48;p=sbcl.git

diff --git a/src/compiler/srctran.lisp b/src/compiler/srctran.lisp
index 943e291..95dfbab 100644
--- a/src/compiler/srctran.lisp
+++ b/src/compiler/srctran.lisp
@@ -179,8 +179,14 @@
 (define-source-transform logorc1 (x y) `(logior (lognot ,x) ,y))
 (define-source-transform logorc2 (x y) `(logior ,x (lognot ,y)))
 (define-source-transform logtest (x y) `(not (zerop (logand ,x ,y))))
-(define-source-transform logbitp (index integer)
-  `(not (zerop (logand (ash 1 ,index) ,integer))))
+
+(deftransform logbitp
+    ((index integer) (unsigned-byte (or (signed-byte #.sb!vm:n-word-bits)
+					(unsigned-byte #.sb!vm:n-word-bits))))
+  `(if (>= index #.sb!vm:n-word-bits)
+       (minusp integer)
+       (not (zerop (logand integer (ash 1 index))))))
+
 (define-source-transform byte (size position)
   `(cons ,size ,position))
 (define-source-transform byte-size (spec) `(car ,spec))
@@ -219,6 +225,21 @@
 ;;;; numeric-type has everything we want to know. Reason 2 wins for
 ;;;; now.
 
+;;; Support operations that mimic real arithmetic comparison
+;;; operators, but imposing a total order on the floating points such
+;;; that negative zeros are strictly less than positive zeros.
+(macrolet ((def (name op)
+	     `(defun ,name (x y)
+	        (declare (real x y))
+	        (if (and (floatp x) (floatp y) (zerop x) (zerop y))
+		    (,op (float-sign x) (float-sign y))
+		    (,op x y)))))
+  (def signed-zero->= >=)
+  (def signed-zero-> >)
+  (def signed-zero-= =)
+  (def signed-zero-< <)
+  (def signed-zero-<= <=))
+
 ;;; The basic interval type. It can handle open and closed intervals.
 ;;; A bound is open if it is a list containing a number, just like
 ;;; Lisp says. NIL means unbounded.
@@ -318,16 +339,8 @@
   (make-interval :low (type-bound-number (interval-low x))
 		 :high (type-bound-number (interval-high x))))
 
-(defun signed-zero->= (x y)
-  (declare (real x y))
-  (or (> x y)
-      (and (= x y)
-	   (>= (float-sign (float x))
-	       (float-sign (float y))))))
-
 ;;; For an interval X, if X >= POINT, return '+. If X <= POINT, return
 ;;; '-. Otherwise return NIL.
-#+nil
 (defun interval-range-info (x &optional (point 0))
   (declare (type interval x))
   (let ((lo (interval-low x))
@@ -338,20 +351,6 @@
 	   '-)
 	  (t
 	   nil))))
-(defun interval-range-info (x &optional (point 0))
-  (declare (type interval x))
-  (labels ((signed->= (x y)
-	     (if (and (zerop x) (zerop y) (floatp x) (floatp y))
-		 (>= (float-sign x) (float-sign y))
-		 (>= x y))))
-    (let ((lo (interval-low x))
-	  (hi (interval-high x)))
-      (cond ((and lo (signed->= (type-bound-number lo) point))
-	     '+)
-	    ((and hi (signed->= point (type-bound-number hi)))
-	     '-)
-	    (t
-	     nil)))))
 
 ;;; Test to see whether the interval X is bounded. HOW determines the
 ;;; test, and should be either ABOVE, BELOW, or BOTH.
@@ -365,32 +364,6 @@
     (both
      (and (interval-low x) (interval-high x)))))
 
-;;; signed zero comparison functions. Use these functions if we need
-;;; to distinguish between signed zeroes.
-(defun signed-zero-< (x y)
-  (declare (real x y))
-  (or (< x y)
-      (and (= x y)
-	   (< (float-sign (float x))
-	      (float-sign (float y))))))
-(defun signed-zero-> (x y)
-  (declare (real x y))
-  (or (> x y)
-      (and (= x y)
-	   (> (float-sign (float x))
-	      (float-sign (float y))))))
-(defun signed-zero-= (x y)
-  (declare (real x y))
-  (and (= x y)
-       (= (float-sign (float x))
-	  (float-sign (float y)))))
-(defun signed-zero-<= (x y)
-  (declare (real x y))
-  (or (< x y)
-      (and (= x y)
-	   (<= (float-sign (float x))
-	       (float-sign (float y))))))
-
 ;;; See whether the interval X contains the number P, taking into
 ;;; account that the interval might not be closed.
 (defun interval-contains-p (p x)
@@ -992,50 +965,53 @@
 	 (member (first members))
 	 (member-type (type-of member)))
     (aver (not (rest members)))
-    (specifier-type `(,(if (subtypep member-type 'integer)
-			   'integer
-			   member-type)
-		      ,member ,member))))
+    (specifier-type (cond ((typep member 'integer)
+                           `(integer ,member ,member))
+                          ((memq member-type '(short-float single-float
+                                               double-float long-float))
+                           `(,member-type ,member ,member))
+                          (t
+                           member-type)))))
 
 ;;; This is used in defoptimizers for computing the resulting type of
 ;;; a function.
 ;;;
 ;;; Given the continuation ARG, derive the resulting type using the
-;;; DERIVE-FCN. DERIVE-FCN takes exactly one argument which is some
+;;; DERIVE-FUN. DERIVE-FUN takes exactly one argument which is some
 ;;; "atomic" continuation type like numeric-type or member-type
 ;;; (containing just one element). It should return the resulting
 ;;; type, which can be a list of types.
 ;;;
-;;; For the case of member types, if a member-fcn is given it is
+;;; For the case of member types, if a MEMBER-FUN is given it is
 ;;; called to compute the result otherwise the member type is first
-;;; converted to a numeric type and the derive-fcn is call.
-(defun one-arg-derive-type (arg derive-fcn member-fcn
+;;; converted to a numeric type and the DERIVE-FUN is called.
+(defun one-arg-derive-type (arg derive-fun member-fun
 				&optional (convert-type t))
-  (declare (type function derive-fcn)
-	   (type (or null function) member-fcn))
+  (declare (type function derive-fun)
+	   (type (or null function) member-fun))
   (let ((arg-list (prepare-arg-for-derive-type (continuation-type arg))))
     (when arg-list
       (flet ((deriver (x)
 	       (typecase x
 		 (member-type
-		  (if member-fcn
+		  (if member-fun
 		      (with-float-traps-masked
 			  (:underflow :overflow :divide-by-zero)
 			(make-member-type
 			 :members (list
-				   (funcall member-fcn
+				   (funcall member-fun
 					    (first (member-type-members x))))))
 		      ;; Otherwise convert to a numeric type.
 		      (let ((result-type-list
-			     (funcall derive-fcn (convert-member-type x))))
+			     (funcall derive-fun (convert-member-type x))))
 			(if convert-type
 			    (convert-back-numeric-type-list result-type-list)
 			    result-type-list))))
 		 (numeric-type
 		  (if convert-type
 		      (convert-back-numeric-type-list
-		       (funcall derive-fcn (convert-numeric-type x)))
-		      (funcall derive-fcn x)))
+		       (funcall derive-fun (convert-numeric-type x)))
+		      (funcall derive-fun x)))
 		 (t
 		  *universal-type*))))
 	;; Run down the list of args and derive the type of each one,
@@ -1051,14 +1027,14 @@
 	      (first results)))))))
 
 ;;; Same as ONE-ARG-DERIVE-TYPE, except we assume the function takes
-;;; two arguments. DERIVE-FCN takes 3 args in this case: the two
+;;; two arguments. DERIVE-FUN takes 3 args in this case: the two
 ;;; original args and a third which is T to indicate if the two args
 ;;; really represent the same continuation. This is useful for
 ;;; deriving the type of things like (* x x), which should always be
 ;;; positive. If we didn't do this, we wouldn't be able to tell.
-(defun two-arg-derive-type (arg1 arg2 derive-fcn fcn
+(defun two-arg-derive-type (arg1 arg2 derive-fun fun
 				 &optional (convert-type t))
-  (declare (type function derive-fcn fcn))
+  (declare (type function derive-fun fun))
   (flet ((deriver (x y same-arg)
 	   (cond ((and (member-type-p x) (member-type-p y))
 		  (let* ((x (first (member-type-members x)))
@@ -1066,7 +1042,7 @@
 			 (result (with-float-traps-masked
 				     (:underflow :overflow :divide-by-zero
 				      :invalid)
-				   (funcall fcn x y))))
+				   (funcall fun x y))))
 		    (cond ((null result))
 			  ((and (floatp result) (float-nan-p result))
 			   (make-numeric-type :class 'float
@@ -1077,21 +1053,21 @@
 		 ((and (member-type-p x) (numeric-type-p y))
 		  (let* ((x (convert-member-type x))
 			 (y (if convert-type (convert-numeric-type y) y))
-			 (result (funcall derive-fcn x y same-arg)))
+			 (result (funcall derive-fun x y same-arg)))
 		    (if convert-type
 			(convert-back-numeric-type-list result)
 			result)))
 		 ((and (numeric-type-p x) (member-type-p y))
 		  (let* ((x (if convert-type (convert-numeric-type x) x))
 			 (y (convert-member-type y))
-			 (result (funcall derive-fcn x y same-arg)))
+			 (result (funcall derive-fun x y same-arg)))
 		    (if convert-type
 			(convert-back-numeric-type-list result)
 			result)))
 		 ((and (numeric-type-p x) (numeric-type-p y))
 		  (let* ((x (if convert-type (convert-numeric-type x) x))
 			 (y (if convert-type (convert-numeric-type y) y))
-			 (result (funcall derive-fcn x y same-arg)))
+			 (result (funcall derive-fun x y same-arg)))
 		    (if convert-type
 			(convert-back-numeric-type-list result)
 			result)))
@@ -2128,27 +2104,19 @@
 	      ;; They must both be positive.
 	      (cond ((or (null x-len) (null y-len))
 		     (specifier-type 'unsigned-byte))
-		    ((or (zerop x-len) (zerop y-len))
-		     (specifier-type '(integer 0 0)))
 		    (t
-		     (specifier-type `(unsigned-byte ,(min x-len y-len)))))
+		     (specifier-type `(unsigned-byte* ,(min x-len y-len)))))
 	      ;; X is positive, but Y might be negative.
 	      (cond ((null x-len)
 		     (specifier-type 'unsigned-byte))
-		    ((zerop x-len)
-		     (specifier-type '(integer 0 0)))
 		    (t
-		     (specifier-type `(unsigned-byte ,x-len)))))
+		     (specifier-type `(unsigned-byte* ,x-len)))))
 	  ;; X might be negative.
 	  (if (not y-neg)
 	      ;; Y must be positive.
 	      (cond ((null y-len)
 		     (specifier-type 'unsigned-byte))
-		    ((zerop y-len)
-		     (specifier-type '(integer 0 0)))
-		    (t
-		     (specifier-type
-		      `(unsigned-byte ,y-len))))
+		    (t (specifier-type `(unsigned-byte* ,y-len))))
 	      ;; Either might be negative.
 	      (if (and x-len y-len)
 		  ;; The result is bounded.
@@ -2163,11 +2131,9 @@
       (cond
        ((and (not x-neg) (not y-neg))
 	;; Both are positive.
-	(if (and x-len y-len (zerop x-len) (zerop y-len))
-	    (specifier-type '(integer 0 0))
-	    (specifier-type `(unsigned-byte ,(if (and x-len y-len)
-					     (max x-len y-len)
-					     '*)))))
+	(specifier-type `(unsigned-byte* ,(if (and x-len y-len)
+					      (max x-len y-len)
+					      '*))))
        ((not x-pos)
 	;; X must be negative.
 	(if (not y-pos)
@@ -2206,11 +2172,9 @@
 	    (and (not x-pos) (not y-pos)))
 	;; Either both are negative or both are positive. The result
 	;; will be positive, and as long as the longer.
-	(if (and x-len y-len (zerop x-len) (zerop y-len))
-	    (specifier-type '(integer 0 0))
-	    (specifier-type `(unsigned-byte ,(if (and x-len y-len)
-					     (max x-len y-len)
-					     '*)))))
+	(specifier-type `(unsigned-byte* ,(if (and x-len y-len)
+					      (max x-len y-len)
+					      '*))))
        ((or (and (not x-pos) (not y-neg))
 	    (and (not y-neg) (not y-pos)))
 	;; Either X is negative and Y is positive of vice-versa. The
@@ -2226,10 +2190,10 @@
        (t
 	(specifier-type 'integer))))))
 
-(macrolet ((deffrob (logfcn)
-	     (let ((fcn-aux (symbolicate logfcn "-DERIVE-TYPE-AUX")))
-	     `(defoptimizer (,logfcn derive-type) ((x y))
-		(two-arg-derive-type x y #',fcn-aux #',logfcn)))))
+(macrolet ((deffrob (logfun)
+	     (let ((fun-aux (symbolicate logfun "-DERIVE-TYPE-AUX")))
+	     `(defoptimizer (,logfun derive-type) ((x y))
+		(two-arg-derive-type x y #',fun-aux #',logfun)))))
   (deffrob logand)
   (deffrob logior)
   (deffrob logxor))
@@ -2318,7 +2282,7 @@
 	     (csubtypep size (specifier-type 'integer)))
 	(let ((size-high (numeric-type-high size)))
 	  (if (and size-high (<= size-high sb!vm:n-word-bits))
-	      (specifier-type `(unsigned-byte ,size-high))
+	      (specifier-type `(unsigned-byte* ,size-high))
 	      (specifier-type 'unsigned-byte)))
 	*universal-type*)))
 
@@ -2333,57 +2297,46 @@
 	      (posn-high (numeric-type-high posn)))
 	  (if (and size-high posn-high
 		   (<= (+ size-high posn-high) sb!vm:n-word-bits))
-	      (specifier-type `(unsigned-byte ,(+ size-high posn-high)))
+	      (specifier-type `(unsigned-byte* ,(+ size-high posn-high)))
 	      (specifier-type 'unsigned-byte)))
 	*universal-type*)))
 
-(defoptimizer (%dpb derive-type) ((newbyte size posn int))
+(defun %deposit-field-derive-type-aux (size posn int)
   (let ((size (continuation-type size))
 	(posn (continuation-type posn))
 	(int (continuation-type int)))
-    (if (and (numeric-type-p size)
-	     (csubtypep size (specifier-type 'integer))
-	     (numeric-type-p posn)
-	     (csubtypep posn (specifier-type 'integer))
-	     (numeric-type-p int)
-	     (csubtypep int (specifier-type 'integer)))
-	(let ((size-high (numeric-type-high size))
-	      (posn-high (numeric-type-high posn))
-	      (high (numeric-type-high int))
-	      (low (numeric-type-low int)))
-	  (if (and size-high posn-high high low
-		   (<= (+ size-high posn-high) sb!vm:n-word-bits))
-	      (specifier-type
-	       (list (if (minusp low) 'signed-byte 'unsigned-byte)
-		     (max (integer-length high)
-			  (integer-length low)
-			  (+ size-high posn-high))))
-	      *universal-type*))
-	*universal-type*)))
+    (when (and (numeric-type-p size)
+               (numeric-type-p posn)
+               (numeric-type-p int))
+      (let ((size-high (numeric-type-high size))
+            (posn-high (numeric-type-high posn))
+            (high (numeric-type-high int))
+            (low (numeric-type-low int)))
+        (when (and size-high posn-high high low
+		   ;; KLUDGE: we need this cutoff here, otherwise we
+		   ;; will merrily derive the type of %DPB as
+		   ;; (UNSIGNED-BYTE 1073741822), and then attempt to
+		   ;; canonicalize this type to (INTEGER 0 (1- (ASH 1
+		   ;; 1073741822))), with hilarious consequences.  We
+		   ;; cutoff at 4*SB!VM:N-WORD-BITS to allow inference
+		   ;; over a reasonable amount of shifting, even on
+		   ;; the alpha/32 port, where N-WORD-BITS is 32 but
+		   ;; machine integers are 64-bits.  -- CSR,
+		   ;; 2003-09-12
+                   (<= (+ size-high posn-high) (* 4 sb!vm:n-word-bits)))
+          (let ((raw-bit-count (max (integer-length high)
+                                    (integer-length low)
+                                    (+ size-high posn-high))))
+            (specifier-type
+             (if (minusp low)
+                 `(signed-byte ,(1+ raw-bit-count))
+                 `(unsigned-byte* ,raw-bit-count)))))))))
+
+(defoptimizer (%dpb derive-type) ((newbyte size posn int))
+  (%deposit-field-derive-type-aux size posn int))
 
 (defoptimizer (%deposit-field derive-type) ((newbyte size posn int))
-  (let ((size (continuation-type size))
-	(posn (continuation-type posn))
-	(int (continuation-type int)))
-    (if (and (numeric-type-p size)
-	     (csubtypep size (specifier-type 'integer))
-	     (numeric-type-p posn)
-	     (csubtypep posn (specifier-type 'integer))
-	     (numeric-type-p int)
-	     (csubtypep int (specifier-type 'integer)))
-	(let ((size-high (numeric-type-high size))
-	      (posn-high (numeric-type-high posn))
-	      (high (numeric-type-high int))
-	      (low (numeric-type-low int)))
-	  (if (and size-high posn-high high low
-		   (<= (+ size-high posn-high) sb!vm:n-word-bits))
-	      (specifier-type
-	       (list (if (minusp low) 'signed-byte 'unsigned-byte)
-		     (max (integer-length high)
-			  (integer-length low)
-			  (+ size-high posn-high))))
-	      *universal-type*))
-	*universal-type*)))
+  (%deposit-field-derive-type-aux size posn int))
 
 (deftransform %ldb ((size posn int)
 		    (fixnum fixnum integer)
@@ -2440,34 +2393,62 @@
      (logior (logand new mask)
 	     (logand int (lognot mask)))))
 
-;;; modular functions
+;;; Modular functions
 
-;;; Try to cut all uses of the continuation CONT to WIDTH bits.
+;;; (ldb (byte s 0) (foo                 x  y ...)) =
+;;; (ldb (byte s 0) (foo (ldb (byte s 0) x) y ...))
+;;;
+;;; and similar for other arguments.
+
+;;; Try to recursively cut all uses of the continuation CONT to WIDTH
+;;; bits.
+;;;
+;;; For good functions, we just recursively cut arguments; their
+;;; "goodness" means that the result will not increase (in the
+;;; (unsigned-byte +infinity) sense). An ordinary modular function is
+;;; replaced with the version, cutting its result to WIDTH or more
+;;; bits. If we have changed anything, we need to flush old derived
+;;; types, because they have nothing in common with the new code.
 (defun cut-to-width (cont width)
   (declare (type continuation cont) (type (integer 0) width))
-  (labels ((cut-node (node)
+  (labels ((reoptimize-node (node name)
+             (setf (node-derived-type node)
+                   (fun-type-returns
+                    (info :function :type name)))
+             (setf (continuation-%derived-type (node-cont node)) nil)
+             (setf (node-reoptimize node) t)
+             (setf (block-reoptimize (node-block node)) t)
+             (setf (component-reoptimize (node-component node)) t))
+           (cut-node (node &aux did-something)
              (when (and (combination-p node)
                         (fun-info-p (basic-combination-kind node)))
                (let* ((fun-ref (continuation-use (combination-fun node)))
                       (fun-name (leaf-source-name (ref-leaf fun-ref)))
-                      (modular-fun-name (find-modular-version fun-name width)))
-                 (when modular-fun-name
-                   (change-ref-leaf fun-ref
-                                    (find-free-fun modular-fun-name
-                                                   "in a strange place"))
-                   (setf (combination-kind node) :full)
-                   (setf (node-derived-type node)
-                         (values-specifier-type `(values (unsigned-byte ,width)
-                                                         &optional)))
-                   (setf (continuation-%derived-type (node-cont node)) nil)
-                   (setf (node-reoptimize node) t)
-                   (setf (block-reoptimize (node-block node)) t)
-                   (setf (component-reoptimize (node-component node)) t)
+                      (modular-fun (find-modular-version fun-name width))
+                      (name (and (modular-fun-info-p modular-fun)
+                                 (modular-fun-info-name modular-fun))))
+                 (when (and modular-fun
+                            (not (and (eq name 'logand)
+                                      (csubtypep
+                                       (single-value-type (node-derived-type node))
+                                       (specifier-type `(unsigned-byte ,width))))))
+                   (unless (eq modular-fun :good)
+                     (setq did-something t)
+                     (change-ref-leaf
+                        fun-ref
+                        (find-free-fun name "in a strange place"))
+                       (setf (combination-kind node) :full))
                    (dolist (arg (basic-combination-args node))
-                     (cut-continuation arg))))))
-           (cut-continuation (cont)
+                     (when (cut-continuation arg)
+                       (setq did-something t)))
+                   (when did-something
+                     (reoptimize-node node fun-name))
+                   did-something))))
+           (cut-continuation (cont &aux did-something)
              (do-uses (node cont)
-               (cut-node node))))
+               (when (cut-node node)
+                 (setq did-something t)))
+             did-something))
     (cut-continuation cont)))
 
 (defoptimizer (logand optimizer) ((x y) node)
@@ -2545,54 +2526,6 @@
 	`(- (ash x ,len))
 	`(ash x ,len))))
 
-;;; If both arguments and the result are (UNSIGNED-BYTE 32), try to
-;;; come up with a ``better'' multiplication using multiplier
-;;; recoding. There are two different ways the multiplier can be
-;;; recoded. The more obvious is to shift X by the correct amount for
-;;; each bit set in Y and to sum the results. But if there is a string
-;;; of bits that are all set, you can add X shifted by one more then
-;;; the bit position of the first set bit and subtract X shifted by
-;;; the bit position of the last set bit. We can't use this second
-;;; method when the high order bit is bit 31 because shifting by 32
-;;; doesn't work too well.
-(deftransform * ((x y)
-		 ((unsigned-byte 32) (unsigned-byte 32))
-		 (unsigned-byte 32))
-  "recode as shift and add"
-  (unless (constant-continuation-p y)
-    (give-up-ir1-transform))
-  (let ((y (continuation-value y))
-	(result nil)
-	(first-one nil))
-    (labels ((tub32 (x) `(truly-the (unsigned-byte 32) ,x))
-	     (add (next-factor)
-	       (setf result
-		     (tub32
-		      (if result
-			  `(+ ,result ,(tub32 next-factor))
-			  next-factor)))))
-      (declare (inline add))
-      (dotimes (bitpos 32)
-	(if first-one
-	    (when (not (logbitp bitpos y))
-	      (add (if (= (1+ first-one) bitpos)
-		       ;; There is only a single bit in the string.
-		       `(ash x ,first-one)
-		       ;; There are at least two.
-		       `(- ,(tub32 `(ash x ,bitpos))
-			   ,(tub32 `(ash x ,first-one)))))
-	      (setf first-one nil))
-	    (when (logbitp bitpos y)
-	      (setf first-one bitpos))))
-      (when first-one
-	(cond ((= first-one 31))
-	      ((= first-one 30)
-	       (add '(ash x 30)))
-	      (t
-	       (add `(- ,(tub32 '(ash x 31)) ,(tub32 `(ash x ,first-one))))))
-	(add '(ash x 31))))
-    (or result 0)))
-
 ;;; If arg is a constant power of two, turn FLOOR into a shift and
 ;;; mask. If CEILING, add in (1- (ABS Y)), do FLOOR and correct a
 ;;; remainder.
@@ -2792,7 +2725,19 @@
     ;; multiplication and division for small integral powers.
     (unless (not-more-contagious y x)
       (give-up-ir1-transform))
-    (cond ((zerop val) '(float 1 x))
+    (cond ((zerop val)
+           (let ((x-type (continuation-type x)))
+             (cond ((csubtypep x-type (specifier-type '(or rational
+                                                        (complex rational))))
+                    '1)
+                   ((csubtypep x-type (specifier-type 'real))
+                    `(if (rationalp x)
+                         1
+                         (float 1 x)))
+                   ((csubtypep x-type (specifier-type 'complex))
+                    ;; both parts are float
+                    `(1+ (* x ,val)))
+                   (t (give-up-ir1-transform)))))
 	  ((= val 2) '(* x x))
 	  ((= val -2) '(/ (* x x)))
 	  ((= val 3) '(* x x x))
@@ -2858,8 +2803,8 @@
 ;;; change.
 (defun same-leaf-ref-p (x y)
   (declare (type continuation x y))
-  (let ((x-use (continuation-use x))
-	(y-use (continuation-use y)))
+  (let ((x-use (principal-continuation-use x))
+	(y-use (principal-continuation-use y)))
     (and (ref-p x-use)
 	 (ref-p y-use)
 	 (eq (ref-leaf x-use) (ref-leaf y-use))
@@ -3249,7 +3194,19 @@
 ;;;; or T and the control string is a function (i.e. FORMATTER), then
 ;;;; convert the call to FORMAT to just a FUNCALL of that function.
 
-(defun check-format-args (string args)
+;;; for compile-time argument count checking.
+;;;
+;;; FIXME I: this is currently called from DEFTRANSFORMs, the vast
+;;; majority of which are not going to transform the code, but instead
+;;; are going to GIVE-UP-IR1-TRANSFORM unconditionally.  It would be
+;;; nice to make this explicit, maybe by implementing a new
+;;; "optimizer" (say, DEFOPTIMIZER CONSISTENCY-CHECK).
+;;;
+;;; FIXME II: In some cases, type information could be correlated; for
+;;; instance, ~{ ... ~} requires a list argument, so if the
+;;; continuation-type of a corresponding argument is known and does
+;;; not intersect the list type, a warning could be signalled.
+(defun check-format-args (string args fun)
   (declare (type string string))
   (unless (typep string 'simple-string)
     (setq string (coerce string 'simple-string)))
@@ -3261,9 +3218,9 @@
       (let ((nargs (length args)))
 	(cond
 	  ((< nargs min)
-	   (compiler-warn "Too few arguments (~D) to FORMAT ~S: ~
+	   (compiler-warn "Too few arguments (~D) to ~S ~S: ~
                            requires at least ~D."
-			  nargs string min))
+			  nargs fun string min))
 	  ((> nargs max)
 	   (;; to get warned about probably bogus code at
 	    ;; cross-compile time.
@@ -3271,24 +3228,23 @@
 	    ;; ANSI saith that too many arguments doesn't cause a
 	    ;; run-time error.
 	    #-sb-xc-host compiler-style-warn
-	    "Too many arguments (~D) to FORMAT ~S: uses at most ~D."
-	    nargs string max)))))))
+	    "Too many arguments (~D) to ~S ~S: uses at most ~D."
+	    nargs fun string max)))))))
 
-(deftransform format ((dest control &rest args) (t simple-string &rest t) *
-		      :node node)
+(defoptimizer (format optimizer) ((dest control &rest args))
+  (when (constant-continuation-p control)
+    (let ((x (continuation-value control)))
+      (when (stringp x)
+	(check-format-args x args 'format)))))
 
-  (cond
-    ((policy node (> speed space))
-     (unless (constant-continuation-p control)
-       (give-up-ir1-transform "The control string is not a constant."))
-     (check-format-args (continuation-value control) args)
-     (let ((arg-names (make-gensym-list (length args))))
-       `(lambda (dest control ,@arg-names)
-	 (declare (ignore control))
-	 (format dest (formatter ,(continuation-value control)) ,@arg-names))))
-    (t (when (constant-continuation-p control)
-	 (check-format-args (continuation-value control) args))
-       (give-up-ir1-transform))))
+(deftransform format ((dest control &rest args) (t simple-string &rest t) *
+		      :policy (> speed space))
+  (unless (constant-continuation-p control)
+    (give-up-ir1-transform "The control string is not a constant."))
+  (let ((arg-names (make-gensym-list (length args))))
+    `(lambda (dest control ,@arg-names)
+       (declare (ignore control))
+       (format dest (formatter ,(continuation-value control)) ,@arg-names))))
 
 (deftransform format ((stream control &rest args) (stream function &rest t) *
 		      :policy (> speed space))
@@ -3305,6 +3261,60 @@
        (funcall control *standard-output* ,@arg-names)
        nil)))
 
+(macrolet
+    ((def (name)
+	 `(defoptimizer (,name optimizer) ((control &rest args))
+	    (when (constant-continuation-p control)
+	      (let ((x (continuation-value control)))
+		(when (stringp x)
+		  (check-format-args x args ',name)))))))
+  (def error)
+  (def warn)
+  #+sb-xc-host ; Only we should be using these
+  (progn
+    (def style-warn)
+    (def compiler-abort)
+    (def compiler-error)
+    (def compiler-warn)
+    (def compiler-style-warn)
+    (def compiler-notify)
+    (def maybe-compiler-notify)
+    (def bug)))
+
+(defoptimizer (cerror optimizer) ((report control &rest args))
+  (when (and (constant-continuation-p control)
+	     (constant-continuation-p report))
+    (let ((x (continuation-value control))
+	  (y (continuation-value report)))
+      (when (and (stringp x) (stringp y))
+	(multiple-value-bind (min1 max1)
+	    (handler-case
+		(sb!format:%compiler-walk-format-string x args)
+	      (sb!format:format-error (c)
+		(compiler-warn "~A" c)))
+	  (when min1
+	    (multiple-value-bind (min2 max2)
+		(handler-case
+		    (sb!format:%compiler-walk-format-string y args)
+		  (sb!format:format-error (c)
+		    (compiler-warn "~A" c)))
+	      (when min2
+		(let ((nargs (length args)))
+		  (cond
+		    ((< nargs (min min1 min2))
+		     (compiler-warn "Too few arguments (~D) to ~S ~S ~S: ~
+                                     requires at least ~D."
+				    nargs 'cerror y x (min min1 min2)))
+		    ((> nargs (max max1 max2))
+		     (;; to get warned about probably bogus code at
+		      ;; cross-compile time.
+		      #+sb-xc-host compiler-warn
+		      ;; ANSI saith that too many arguments doesn't cause a
+		      ;; run-time error.
+		      #-sb-xc-host compiler-style-warn
+		      "Too many arguments (~D) to ~S ~S ~S: uses at most ~D."
+		      nargs 'cerror y x (max max1 max2)))))))))))))
+
 (defoptimizer (coerce derive-type) ((value type))
   (cond
     ((constant-continuation-p type)
@@ -3584,5 +3594,5 @@
       (format t "/(CONTINUATION-VALUE X)=~S~%" (continuation-value x)))
     (format t "/MESSAGE=~S~%" (continuation-value message))
     (give-up-ir1-transform "not a real transform"))
-  (defun /report-continuation (&rest rest)
-    (declare (ignore rest))))
+  (defun /report-continuation (x message)
+    (declare (ignore x message))))